heres my analysis of the protaganist.
ORIGINS OF THE CHARACTER – Aku no Hana has a very strong autobiographical component. Emblem of this, it is the character of Kasuga, perfect transposition of Oshimi as a boy. Obviously I’m not referring to the events of the manga, but to the feelings and the psychological state in which Kasuga is found.

The author tells how his childhood in the town of K. (the full name is not known) in the prefecture of Gunma was pervaded by restlessness. Oshimi despite having a normal family and a quiet school life, he spent his days in solitary anguish. In the morning he would go to school and in the afternoon he would spend it alone, either on the river bank or on the school emergency stairs, reading everything he could find in the small library in the center or what his father lent him. In the evening, as he returned home at sunset, because of the lack of artificial lighting, he saw the little town that was slowly engulfed by the darkness; this feeling tormented him on daily basis. It is this sensitivity that leads him to alienate from his classmates, and to create a wall between himself and others. Oshimi didn’t feel part of society, he didn’t see himself like them, so he created a mask of haughtiness: “I read Baudelaire, while you do not even know who he is.” But this is just a mask, the Oshimi himself says that Flowers of Evil is not a reading indicated for a twelve-year-old boy, so much so that, even on his own admission, at the time he did not understand it at all, but he boasted that he had understood it only for show yourself “cool”.

FIRST PART – With this premise you can perfectly understand the first part of the manga. What Kasuga does is a slow descent towards nihilism. Nakamura shows him the way, but it is he who wants to follow it. The spark that begins this descent, the first flowering of his “aku no hana” is obviously the theft of Saeki’s gym suit. This act Kasuga does it by himself, and as far as he justifies it, he knows very well that he has made a bad thing. He could have solved this mistake in a variety of ways, but he never does it; and the blackmail of Nakamura never existed, the psychological pressure comes from him and not from Nakamura. I say this because assuming that Nakamura had told everyone about it, it would simply be her word against that of Kasuga; and between the two, the teachers would have believed the latter, given the reputation of Nakamura. The intent of Nakamura, and she too repeatedly affirms it, is to eliminate the moral preconceptions imposed by society, the super-ego, by quoting S. Freud, so that Kasuga could become “abnormal” like her. In fact, the alleged psychological terror of Nakamura lasts until the episode of vandalism of their class. After that moment Kasuga abandons any connection with society, emblem of this is his renunciation of Saeki’s love. From that moment on, Kasuga lives exclusively to have the approval of Nakamura, or rather, after reading her diary, he is convinced to be like her, and therefore the only person who can save her from her illness. The culmination of this nihilistic descent is the attempted suicide, in which he is stopped by Nakamura as it is still considered too “normal”.

SECOND PART – In the second part of the manga, or after the transfer, Kasuga seems to have returned to “normality”. He tries to survive in society, always shy and aloof. In one way or another he managed to doze his impulses of destrudo, the “aku no hana”, certainly due in large part to the absence of Nakamura. However, it should not be underestimated what brought it first in that state: literature. Kasuga tells Tokiwa more than once that he has not read a book since he moved. This seems to be the confirmation of how literature has played an important role in everything that happened in the past. Despite this, after discovering that Tokiwa shares his same passion for reading, he returns after years to read (marvelous scene in which Kasuga sees Tokiwa in that small library intent on choosing a title, and Kasuga feels as if he was seeing himself in the mirror). They then start dating, exchanging volumes and titles of novels. Although they are clearly made for each other, Kasuga is still dominated by his nihilistic thoughts. To escape this mental prison, the fortuitous meeting with Saeki is fundamental. From this Kasuga understands how, up to now, he had tried to defeat his nihilism through the wrong battles, dedicating his life to what he could not understand: the work of Baudelaire (as admitted by the same author) and the unattainable Nakamura. However, he hears something more in Tokiwa’s novel, something that he really feels to belongs to me. He then manages to decipher the message behind her novel, and becomes aware of the fact that only he is able to save her from the misery of her existence. So he rushes to Tokiwa to declare his love. Together they can win the battle against the “aku no hana”. Kasuga take his life in his hand, he finally found the end of his puberty.

Upon Tokiwa’s request, Kasuga decides to face his past: meet Nakamura. When he comes face to face with her on the beach, Kasuga cannot say anything clever, and if Tokiwa had not intervened, he would have fled once again from his past. After Tokiwa’s touching intervention, Kasuga runs to Nakamura, and hugs her tightly in his arms, but it is only a moment, because soon after he throws her to the ground with all his strength and from there begins a scuffle with her, in which Kasuga pulls also Tokiwa inside. A beautiful scene, empty of dialogues but full of meaning. In it there is the feeling of love (embrace) and hate (the shove) that Kasuga has against Nakamura, and the struggle that follows is the symbol of Kasuga’s growth, no longer afraid of Nakamura, can face it on equal terms, because he has Tokiwa at his side (for this he pulls her into the fight). Once exhausted by fatigue, Kasuga tells Nakamura that she is happy that she has not disappeared, because the past cannot be erased, it can only be accepted.