Desire for StrengthWhen he was younger, Akihiko lost his younger sister, Miki, in a fire. The circumstances are never explained in detail, but it is very clear he feels completely responsible for her death. The two siblings grew up in an orphanage because they didn't have parents. Additionally, there were no other kids around Miki's age there so she didn't have any friends, either. Akihiko recalls how she used to follow him around everywhere. He likely took it upon himself to take care of her not only as her older brother, but as a caretaker in absence of parents as well. Most people, especially children, would be devastated if they lost their sibling suddenly. Akihiko definitely experienced tremendous grief. However, also filling a caretaker role for Miki and simply being a child himself complicated his feelings to include terrible guilt and anger. If only he had been there or done something differently, maybe she wouldn't have died. It was his responsibility to look after her. He was the only thing she had and he let her down! Further, she was only a little girl. Akihiko anguishes to the protagonist over the fact that Miki never got to experience anything good in life:
"Why...did she have to die? She was so small... She never knew her parents' faces, or had good food to eat, or got to have any toys... She had nothing..."I found it interesting that during this scene, Akihiko goes from saying he was the only thing she had to saying she had nothing at all. I feel this change is another indicator of his guilt that pushed through once his emotions started to overwhelm him. If he had truly been there for her, she wouldn't have died. What good was he if he couldn't even protect his younger sister? With trembling lips, he recalls to the protagonist a saying about how being alive is a sin. Simply by bringing this up combined with the emotion during this moment was another huge indicator of the amount of guilt he is carrying. He would even go so far as to say him being alive when she died is a sin. His feelings of sadness, anger and guilt are so powerful, he feels like he can't do anything about experiencing them and therefore has to live with them for the rest of his life.
Due to the enormous amount of guilt that Akihiko feels, he decides his only option after her death is to get stronger. He did not want to lose anyone else and the strength he was missing to protect Miki was something he needed in order to protect others. In fact, getting stronger wasn't even an option--he had to do it. I think there are a couple reasons why Akihiko henceforth became so obsessed with strength. First, he felt terrible about himself. He had strong feelings of helplessness and incompetence because he was unable to save Miki. By getting stronger and bettering himself in any way possible, he could mentally counteract the negative feelings he harbored. Akihiko would rise to the top in order to balance out his heart plummeting to the ground. Further, Akihiko had to feel like he was doing something to make up for what he "did." He kept telling himself that by getting stronger, he was doing "everything that [he] could." To me, this quote indicated getting stronger was his way of making up for his inability to do anything when she died. As long as he was doing something, perhaps the guilt would ease.
Second, focusing on something besides Miki's absence functioned as a defense mechanism for him. Akihiko was clearly overwhelmed by powerful emotions and resented those feelings. No one wants to feel grief, anger or guilt. He later admits to the protagonist that part of him wanted to forget Miki because it was too painful; he didn't want to face what happened. Pouring his heart, mind and soul into getting stronger enabled him to forget about everything else. As a defense, Akihiko forced himself to have "tunnel vision," where he hardly thought about anything other than his goal. Unfortunately, a defense mechanism is only truly helpful in the short-term. It is useful in that it temporarily reduces stress in order to function, but can be harmful if prolonged because the person doesn't end up dealing with their negative feelings. Akihiko didn't have a chance to go through the grieving process. He went through denial, anger and a lot of self-blame, but he never came to terms with the loss. He was simply pretending he accepted Miki's death. Focusing on bettering himself certainly helped Akihiko get by each day, but it was not doing anything to reduce those emotions when they came up. Akihiko would have to face his feelings if he wanted to truly make peace with the past.
Luckily with the help of the protagonist, Akihiko is able to face the past and resolve the guilt, anger and sadness he had been carrying for years.