In first year, Katie knew that Cho existed, how could she not? Cho was the first person that Katie noticed had been sorted after her own sorting. There was probably a person or two between them, but it was just the amount of time for her to tune back in. Years later, Katie would be able to remember a peripheral thought of: 'Oh, she's pretty' echoing through her head. But then Cho, the pretty girl, was sorted into Ravenclaw, and Katie all but forgot about her in the excitement of discovering all there was to know about magic.
Second year started out full of excitement for Katie. Harry Potter, the boy-who-lived, someone she'd heard an awful lot about since joining the Wizarding World, had been sorted into her house; It was terribly exciting. Then, it was time for Quidditch tryouts- Wood was so overenthusiastic that he set them for the second day of classes. And, by the end of the day, Katie Bell, second-year muggleborn, was a lead chaser for the Gryffindor Quidditch team. The Weasley twins also made the team that day, and a small part of Katie wondered if Wood deliberately chose younger people that were less talented over older, better, people, to make the team last longer. After all, he had been traumatized by losing over half the team when they all graduated. But then, she mounted her broom, and any feelings of inadequacy melted away.
That is, until it was time for her first match. It was difficult enough being one-upped by a first year making the team, even if that first year was the boy-who-lived or whatever, but when she stepped onto the pitch, she saw in a sea of beefy boys- little Cho Chang. And Katie saw red. Not the red of Gryffindor's Quidditch robes, though she saw that too, the red of fury. The red of blazing hot anger, that comes from feeling your accomplishment seep between your fingers. Katie was supposed to be the young prodigy on the Quidditch pitch, not Harry Potter, and certainly not prissy Cho Chang. Just in time, Katie was able to shake these feelings well enough to get on her broom and fly like her life depended on it. She put quaffle after quaffle inside those rings that definitely looked like bubble blowing wands, and disrupted the Ravenclaw chasers' plays time after time.
Katie was taking a quick break while the quaffle was across the pitch from her when she saw her chance. Cho Chang was flying right at her, in clear pursuit of the snitch. Katie continued to drift a bit until Cho was in the perfect position, and then, Katie accelerated directly into Cho. Harry, who it turned out was somewhere behind Cho, was able to catch the snitch, thus ending the game and preventing Katie from facing any in-game consequences for her clear and blatant foul. As she disembarked from her broom, she was bombarded by Madam Hooch who gave her a loud speech about the importance of good sportsmanship followed by congratulations from Oliver. But she hardly heard any of it. Katie only had eyes for Cho Chang, who was standing at the edge of the crowd, and death glaring right back at her.
Katie's third year was consumed by devoting herself to Quidditch. It was all that kept her sane that year. If she had slowed down just once to let herself think, she began to panic about the horror in the Chamber. It was better to escalate her rivalry with Cho by committing gradually more egregious fouls to interfere with her catching the snitch, than to slow down. This year, Katie came the closest she ever came to murdering Fred and George Weasley, and she would forever say that she had a reasonable motive. That stupid betting pool they set up over when she and Cho would get together was stupid and insulting. And so, to keep herself distracted and from murdering anyone, she practiced every waking moment she could spare; if nothing else, Wood commended her dedication.
Fourth year was another difficult year for Katie. Despite not being targeted personally by the dementors, they made her feel like she did all year last year, and that was not something she was pleased to have to experience again. Nevertheless, she continued the rigorous training schedule she had set for herself, passing by dementors on bravado alone to make absolutely certain she was in top form to best Cho. How such a snotty rich girl could even be interested in playing Quidditch was beyond Katie, but whatever the reason, Cho was interested in Quidditch, and it was Katie considered it her personal duty to take her down a peg.
After a particularly vicious match in which Cho spent the entire time interfering with Katie's plays and successfully preventing her from scoring all but one goal, Katie was feeling pretty down. She put away her material and changed into her normal clothes in the locker room and headed out to the lake for some alone time. Gryffindor might have won the match, but it had been a loss for Katie.
As she was getting up from the lake shore, she heard a shout of distress coming from further along the lake. Her foolishly Gryffindor tendencies kicked in, and she began to run towards the sound. As she got nearer, the sounds changed from yelling to sobbing, and Katie pushed herself to run faster, harder, she had to get there now. When she came into view, she saw a dementor prying at Cho's hands, which she had clasped over her mouth, and without thinking, Katie pointed her wand and cast the strongest protego that she'd ever cast. The dementor was rebuffed long enough for Katie to cast Wingardium Leviosa on Cho, grab the now floating girl, and run. Katie didn't stop running until they were inside the castle doors, at which point she canceled the spell and collapsed on the ground. After a few minutes of laying on the ground regaining energy, Cho got up, brushed herself off and spat, "I didn't need your help," at Katie, who was still lying on the ground. Katie forced herself into a sitting position, and yelled, "Then fine, next time I'll leave you to be kissed!" at Cho's retreating back. As Cho's robes whipped around the corner, Katie lay back down, and asked herself why she cared if Cho had some chocolate to eat. She would deny for years after, that she was the one to send Cho some of Honeyduke's finest chocolate.
Fifth year was yet another difficult year for Katie. The Quidditch Cup was canceled for that stupid Triwizard Tournament or whatever, and all Katie had left to do with her time was school work, and sure it was her O.W.L. year, so this was probably a good thing. Probably. It was hard to convince herself of that when her feet were firmly planted on the library ground, but her head and heart were flying after the quaffle in the sky. Strangely enough, some of these daydreams featured a flash of black, silky hair.
When Katie heard that Cho was going with Cedric Diggory to the Yule Ball, she had to face her feelings for Cho. It was now clear to Katie that Fred and George had been right about at least one thing all along. Unfortunately, it seemed that they were doomed to be wrong about her and Cho ever getting together. Katie told herself that she would be happy for Cho, even though they were bitter rivals on the pitch because she really did seem happy with Cedric. And anyways, it's not like their rivalry ever left the Quidditch pitch, so it'd be really awful of her to act jealous. And anyways, jealousy would prevent any chance of friendship with Cho.
Her determination to be happy for Cho couldn't seem to stop her from sobbing to You Belong with Me on eternal repeat after the Yule Ball. She was honestly so thankful for silencing spells because she made the ugliest noise every time she heard the lyric:
Can't you see that I'm the one who understands you? Been here all along so why can't you see, that you belong with me?
By the time the sun rose the next morning, however Katie had cleaned herself up and made herself presentable for classes, because goddamnit she was going to be happy for Cho.
The second task was nerve wracking for Katie, she was able to tell in minutes that Cho wasn't in the stands, and she just knew that she was at the bottom of the lake. Katie would have given anything to be allowed to save Cho, she was a Gryffindor after all, and it was almost physically painful to have to sit in the stands while Cedric got to actually do something. But somehow, she made it through the task without diving into the lake herself.
The rest of the year was spent buried in her course work, trying to ignore her feelings that were annoyingly persistent and reawakened by the slightest contact with Cho. And honestly? Katie almost died when one day in Charms she stretched, revealing a strip of skin that Katie couldn't seem to look away from. It lead to a very embarrassing blunder on a charm that she definitely knew how to do.
Despite all this, Katie somehow managed to make it to the end of the year. Not only that, she was pretty sure that she'd nailed her O.W.L.s! Of course, she'd rather not have to use them, given that her ultimate goal was to join a professional Quidditch team, but it was good to know that she'd probably have options. But at the moment, professional goals were the least of Katie's worries. She was in the stands for the third task, and Harry had just appeared with Cedric's body.
Looking around for Cho, Katie was buffeted by people rushing out of the stands, and maybe Katie ought to just go with the crowd, but she knew Cho had been somewhere behind her. After a few seconds, Katie realized she was being a moron and turned around and looked towards Cedric's body. And sure enough, there was Cho. How she'd ever managed to get through the crowds so quickly, Katie didn't think she'd ever know. She also had a few of her friends with her, so Katie decided, regretfully, that she wasn't needed.
Finally moving with the crowd, Katie let herself be carried towards the castle doors where everyone was being guided by the faculty, but before she could be carried in, Katie broke away from the crowd once more and headed towards the Quidditch locker rooms. The Quidditch pitch may be ruined at the moment, but that was no reason that Katie shouldn't fly.
Katie was in the middle of a corkscrew maneuver when she saw that she wasn't alone. Upon leveling out her flight, she saw that is was Cho; and she seemed deeply upset. To be fair, she had every reason in the world to be- her boyfriend had just been brutally murdered after all. Katie had no idea what she was supposed to do in this situation.
She and Cho were just Quidditch rivals, they weren't even friends- so should Katie taunt her like she would do before a match? Obviously not, but what else could she do? Katie supposed that she could just leave, but that would probably hurt Cho, to be abandoned like that, even if it was just by her Quidditch rival. So, leaving was out, their normal interaction was out…god Cho was pretty…
And then, she nearly flew into a copse of trees by the lake. Katie was incredibly embarrassed, she'd never come that close to doing something so stupid in the air. She glanced back over at Cho, who was lazily circling nearby, and saw that she had the smallest smile on her face, despite the tears that were still flowing down her face.
Katie smiled in response, and flew over to Cho, "Guess that was pretty stupid of me."
"Yeah, you could have gotten really hurt, or," Cho paused, "something worse," Cho glanced away and wiped away a few tears.
Katie really wanted to just wipe all the tears off Cho's face and pull her into a hug and never let her go, but instead, she said, "Ah I'm sure I would've been fine! There's clearly not too much to hurt inside my head."
"Don't say that! You're one of the best at transfiguration that I know! Not to mention how good at flying you are!" Cho exclaimed, whipping around to stare at Katie intensely.
Katie wasn't sure her ears were functioning properly. Cho had just complimented her? A real, genuine, compliment? She realized that her mouth was hanging open and hastily closed it. She and Cho had been drifting around the lakeshore together, and Katie turned to look at Cho, only to realize that Cho was sobbing near silently.
Katie reached over and gently grasped Cho's broom. She guided them towards the shore and caught Cho before she could collapse on the ground. She and Cho ended up sitting on the sand together, brooms discarded, and Cho slumped against Katie's shoulder, still sobbing.
Feeling incredibly awkward, Katie began to rub Cho's back, making comforting noises, and hoping that she wasn't making things worse.
Eventually, Cho stopped crying, and straightened up. She started wiping at her face, and looked away as though she were embarrassed.
Katie reached out and put her hand on Cho's shoulder, "Hey don't worry about it. Today's been awful."
Cho let out a wet laugh, "Yeah that's the understatement of the century."
Katie and Cho sat together in comfortable silence, just staring at the stars and mulling over their own thoughts.
Eventually, Katie broke the silence. "Is there anything I can do?" she asked tentatively.
Cho seemed to ponder this for a moment. Then, she stood up, grabbing her broom, and said, "Yeah I'd really like to fly for a bit. Will you join me?"
Katie rocketed to her feet and nearly tripped when she tried to grab her broom. When she'd righted herself she said, "I'd love to!"
That summer, Katie and Cho started a correspondence and deepened their friendship. By the time they went back to school, Katie and Cho considered each other best friends.
Every opportunity Katie got during sixth year, she spent time with Cho. They studied together, flew together, and had deep conversations by the moonlit lake. In short, they spent time together at every possible chance. However, they maintained their rivalry on the pitch; but now, it was a friendly rivalry. Their taunts had lost any bite that they might have had, and were often accompanied by a sly smile.
Occasionally, Katie felt like she was lying to Cho, or misleading her, because Katie hadn't told Cho about her massive crush on Cho. But whenever those feelings came up, Katie distracted herself until she forgot about them.
Life continued though, and their seventh year started out happily enough, when the developing war was disregarded, but Katie was having a harder time than ever ignoring her feelings for Cho. She tried to satisfy herself with their friendship, but it was getting harder and harder.
In October, Cho asked Katie to go to Hogsmeade with her as they'd been doing for the past year or so, and Katie said yes as always. When they were at the Three Broomsticks, Katie went to go to the bathroom, but, unlike last year, something happened while she was there, because the next thing she remembered was waking up alone in St. Mungo's.
After a battery of tests and treatments, her parents were finally allowed to see her. It was great to see them again. It was weeks before she was able to hold a conversation, but when she was, she took the opportunity to ask them what to do about Cho. Both her moms encouraged her to confess her feelings, which was honestly shocking because her moms were usually the bicker and disagree type. Katie resolved herself to tell Cho everything the next time she saw her.
It was April by the time Katie was released to go back to school, and she had been itching to get back for ages. As she walked through the castle to Ravenclaw tower, she rehearsed what she would say to Cho again. She'd had the words planned for months- there really wasn't much to do in the hospital besides school work.
As she slowly made her way down a corridor, she saw Cho come around the corner. Her hands were full of books, so she must have been heading to the library. Katie started walking faster, and as she did, she made eye contact with Cho, and as soon as she did, Cho dropped her books, and started running towards Katie.
Katie opened her arms and braced herself, because it was clear that Cho had no intention to slow down. Cho grabbed Katie in a hug and spun her around, both of them laughing happily. They bumped into a wall, and still hugging Katie, Cho leaned down for a kiss.
Katie reciprocated after a few seconds of stunned stillness. Then, she slid her tongue into Cho's mouth. Katie reveled in the taste of her mouth. This was what Katie had daydreamed about for years now, and it was everything she had dreamed it would be.
All good things must come to an end, and so too did their kiss. Katie broke away from Cho and took a deep breath. Cho leaned in for another kiss, but as much as she wanted to, Katie put her palm on Cho's chest and shook her head, "We really should talk, you know," Katie said, a little breathlessly.
Cho pouted, and Katie nearly lost her resolve and leaned in to kiss her again, but she just managed to stay strong. "I've wanted to do that for years," Katie admitted.
"So have I, and so much more," Cho said, tracing Katie's jawline and being otherwise incredibly distracting.
Katie took a deep, shuddering breath and leaned into Cho's hand, "I guess we don't have too much to talk about then. Will you be my girlfriend?"
Cho nodded, and leaned in for another kiss.
Katie was able to catch up on her school work with the help of Cho, and take her N.E.W.T.s on time. Unfortunately, her plan to join a professional Quidditch team was derailed by Voldemort and her blood status.
Cho helped her go into hiding, and she lived in France anxiously scouring the news for word of Cho and with an eye always on the sky, watching for an owl. One day, that owl did come. It was time to go return to Hogwarts. The final battle was upon them.
When Katie arrived in the Room of Requirement, the first person she saw, and the only person she had eyes for was Cho. They stole a quick kiss that was no less passionate for its brevity, before heading into the fray.
They tore through the Death Eaters, leaving no survivors. Katie and Cho were the perfect team, able to anticipate each other's every move, a skill learned on the Quidditch pitch and honed through many private dueling practice sessions.
Somehow, somehow they both made it to that courtyard, and Voldemort declared Harry dead. Katie turned to Cho, ready to share one last kiss before going down fighting. And she saw in Cho's eyes the same certainty and felt that passion in their kiss.
Then, Neville was decapitating that horrid snake.
Then Harry was getting up!
Then Voldemort and Harry were dueling.
Then everyone started fighting.
Katie and Cho headed right back into the fray. They managed to take down a few more Death Eating scum.
Then, Voldemort was dead.
And time seemed to stop.
The battle ended quickly after that.
There were still death eaters to catch, but that was a job for the Auror's.
Cho began her higher education.
Katie was contacted by several Quidditch teams that had lost players to the war.
Cho moved into Katie's flat.
Katie proposed to Cho.
Cho said yes.