Kotonoha doesn't have such a thing called "childhood".
As a daughter of a prominent family, she must study vast knowledge, ranged from piano to chess, penmanship to painting, tea ceremony to dancing, martial arts to ikebana…from young, very young. The reason is quite simple: She's a daughter of a prominent family.
No refusal, no complaint, no protest…must maintain a well-endowed lady's manner all the time, all the occasions. The reason is quite simple: She's a daughter of a prominent family.
Years past, Kotonoha utilizes a "black hole armor" policy to face everything, especially when being misunderstood or bullied by others, she absorbs all attacks and in return, a polite smile.
Smile is supposed to be a power of communication and cure. But Kotonoha's smile is abnormal and unreal, because a normal person never smiles when at a tough point. Since she doesn't know how to release her emotions via a proper way, she eventually enters berserk mode. Qu Yang can't do anything about this: Kotonoha had "instinctlized" concealing emotions in depth of her heart, even in front of her most trusted friend, she still refuses to discard the mask.
From that day on, Kotonoha's school days are divided in to two parts. When with Makoto, she keeps her smile, gentle and firm, makes best efforts to adapt the role of "Makoto-kun's girlfriend". Although she politely deflects all of Makoto's sexual requests, but even a moron can see her feelings to him.
Kotonoha still considers Sekai as her intimate friend. When the two girls are together, they talk and chat happily as nothing happened. But when they're not looking at other, Sekai's expression is always slightly guilty as Kotonoha's is much more complicated.
Qu Yang records everything by his eyes. The gauge has been filled by 25%, means Kotonoha has reached the first level of berserk.
When not with friends, Kotonoha is still bombarded by Otome and other students. This day, when she finishes dating Makoto and backs to classroom, Otome and her companions had readied another wave of attack. Poor girl, unwilling to retaliate, just lowers head on to her soaring bosom with piteous expression. But on contrary, her actions results them to attack even intenser.
Kumi jealously stares at Kotonoha's chest's immense and beautiful-shaped melons: "How many boys had been deceived by you? That foreign student…" She chocked since a wooden blade, appears between she and Otome's heads from no where, like a teleportation.
"Kotonoha, could I have the honor to practice some martial arts with you?" Qu Yang, holding two wooden blades, comes to rescue.
Kotonoha, like a little child who is being bullied, finally meets her parents. Her tearless eyes are filled with surprise: "はい！But…where can we practice?"
Qu Yang: "The rear sector of classroom is empty enough." Kotonoha nods.
Qu Yang glances at the gauge as he tosses her a blade. The reading reaches 31%.
Of course Otome's gang has retreated to a safe distance. They are afraid of Qu Yang, not to speak of an armed one.
Then the students are lucky to watch a highly skilled performance of martial art. Or more accurate, unilateral offense and defense.
Kotonoha with blade in hand, barely can be recognized as a delicate and touching girl. Fast like lightning, strong as tsunami, she attacks Qu Yang in a manner of Hurricane Katrina (Note: Kotonoha's most proficient martial art is Iaido, which is very different from common Kendo. Unlike common Kendo is concentrated on prolonged combat, Iaido is specialized in vanquish targets by one swift strike on vital points. It's not specified whether she is also proficient at other types of martial arts, but there are possibilities).
If Kotonoha's martial art skill can be described as "amazing", Qu Yang's skill only can be described as "terrorizing". He stands lazily, but as if being protected by A.T. Field or Iron Curtain, easily deflects all the attacks from Kotonoha.
During the progress, Qu Yang doesn't forget to instruct the girl:
"One centimeter below!"
"More accuracy!"
"Use more strength!"
"Not all strength! Only drain 70%! Other 30% is for switching pattern!"
As Kotonoha increases power output, Qu Yang steps back little by little, until he reaches the wall. Then he says: "Be careful, my move."
Qu Yang initiates counter-strike, Kotonoha is forced to back off. No matter how she changes defensive patterns, his blade always hits on the same point.
When Kotonoha backs to the original position, Qu Yang stops: "Excellent. I used one more round than last time."
Kotonoha: "Kuyou-kun is perfectly on my peak point all the time, my wrists will be injured if you attack a little harder." As you can see, Qu Yang will never "hurt" her.
Other students still not recovered from shock: Is Kotonoha Katsura still that Kotonoha Katsura they know? And that Chinese, he's legendary!
Suddenly Kotonoha realizes they're being watched by so many people, she immediately hides herself behind Qu Yang.
"They should be a couple…" Someone recalls the complicated relations between Kotonoha, Makoto, Sekai, Qu Yang.
Qu Yang glances the gauge, the reading slightly reduces, now on 29%.