Author's Note: I don't own Naruto. This takes place shortly after Minato gets his Genin team, and before he's Hokage. It takes a bit to get to the adventurish part. This is written for the FanFiction High-School Never Ends (BIG challenge).
Rin was trailing behind Kakashi, Minato, and Obito on the way to get some ramen to celebrate the success of their mission, even though the mission was to harvest a farmer's field. Minato held the door open for his students, before following them to a table. Rin sat next to Kakashi, leaving Minato a spot by Obito. Minato was about to sit down, but was interrupted by Inoichi, who handed him a file before leaving. Minato's students stared at Minato expectantly. Minato stared back at his students with a look of complete confusion on his face. Obito sighed, "Well? Aren't you going to open it?"
Minato shrugged, "Not with the three of you staring at me like that. It's probably important."
"Like ANBU important?" Minato's expression was answer enough to Obito's question. Obito grinned, "Yay! Not even Chunin yet, and they want us to go on an ANBU mission! We rock!" Kakashi and Rin looked just as honored as Obito did.
Minato had opened the file, while his team was distracted, and couldn't help but to start laughing, "It doesn't mention you guys at all."
His entire team looked crushed and betrayed, "What do you mean it doesn't mention us? Who else would you go with?"
Minato shrugged, "It's a solo mission."
Rin looked horrified, "But what if you get hurt? Who's going to help you?"
Minato shrugged, before laughing, "I can take of myself, I've been doing it for awhile now." His team didn't look any less horrified, and he couldn't blame them. He wasn't exactly the best at bandaging injuries, or cooking. Minato pulled out some money and handed it to Kakashi, "You guys get something." With that, he got up to leave and successfully made it out of the restaurant.
His team sat at the table in silence, trying to decide what to do. The only things that they had heard about solo ANBU missions were how many people died during them. Unfortunately for Minato, his team had decided that they liked him and weren't going to let him become another name on the Memorial Stone. Obito stood up, "Let's follow him!"
Kakashi rolled his eyes, "It's a solo mission, and he didn't request back up. There's no reason to follow him."
Obito grinned, "You don't think we can do it."
Kakashi frowned, "Let's go!" He began to lead the way out of the restaurant followed by Obito and Rin, who were both grinning. The three young Genin began to walk through the woods to get out of the village, to feel more stealth like, and to hopefully avoid getting caught by any adults. The beginning of their journey was rather plain, but then it started to get dark out. Obito looked over and threw a kunai at what he thought was a giant snake that was gonna eat Rin, but Kakashi didn't hesitate to point out that it was only an overgrown weed that Obito had saved Rin from. Obito's face had turned bright red, as they continued on their journey to save their Sensei from any danger that he could possibly experience.
The three children continued to walk blindly in the dark. The two boys stopped walking when they heard Rin scream, and they realized that she managed to fall over a tree branch that was above the ground. Obito rushed over to help her up, while Kakashi watched them, "Are you okay?"
Rin nodded, "I'm fine. I just scraped my knee a little. But, let's keep going we have to catch up to Sensei!" The three Genin continued on their way, and were beginning to doubt their ability to catch up to Minato for multiple reasons. One being that he was considered the Yellow Flash of Konoha, and the other being that they had no idea where he was even going.
Along the way, many trees, roots, leaves, bushes, and weeds got kunais attacked, for being mistakened as other, actual threats. Kakashi continued to lead the brave mission against the forest when he heard a branch move. He looked around and could tell that Rin and Obito had noticed it as well. He quickly shushed them to keep them from alerting a possible threat of their presence, even though they were in the wide open. The three Genin pulled out kunais and prepared to defend themselves.
Minato sat in the tree, and looked down. He sighed, of course it'd be his students in the middle of the woods in the middle of the night interfering with an ANBU mission. Minato came down from the tree and was preparing to scold his team for being reckless, along with many other things. His lecture was interrupted by the kunais getting thrown at him. The three Genin looked completely mortified when he actually saw their expression. From their perspective they were defending themselves from a dangerous threat that just dodged three kunais at the same time and they had no way to escape. Minato then realized that he still had his unusual ANBU mask on, and that he was terrifying his team. He took the mask off, and shortly after was tackled by three children, two of which were crying. He sighed, as he realized that he'd have to set up camp here, since he wasn't going to get far with the clingy children. He decided that he would take the children back to the village in the morning, and head out again in the morning. He sighed when he looked into his tent to see the three children sleeping and taking up all the room. He sat outside of the tent and spent the rest of the night doing surveillance, while his team slept, exhausted from their dangerous adventure.