ResolutionsPersona 3 is a great game in regards to character development. All of the main characters have their own individual struggles in the past and present they eventually overcome. Arguably, when they are able to triumph over their past or find a solution to their present difficulty, they take a step forward in their own development. The following scenes are those in which Akihiko grows as a character and forms a new resolution that represents said growth.
Shinjiro's SacrificeShinjiro is shot multiple times by Takaya in order to protect Ken and Akihiko is severely impacted by his best friend's death/falling into a coma. Shinjiro was always Akihiko's support system; What would he do without him? If the female protagonist maxes out Shinjiro's social link, Akihiko goes to the hospital to talk to him even though there is a "no visitors allowed sign." If not, or the player is being the male protagonist, Akihiko talks to Shinjiro at his memorial. Akihiko laments over Shinjiro's condition and admits he has been too obsessed with power since Miki's death. He thought as long as he was strong enough, he could protect anyone. Clearly he was wrong. He lost/may lose Shinjiro, too. Akihiko sobs and begs him not to leave him behind. Pulling himself together, he stands up and says, "yeah, I know... Crying won't change anything, will it?" as if Shinjiro were conscious. Akihiko realizes he has things to do still which need to take precedence over his grief. He wouldn't want him to wallow, anyway. Akihiko is then able to use his deep respect and love for his best friend as strength to continue forward. I think Akihiko saw Shinjiro's resolve for atonement through his sacrifice and was inspired to find his own resolve. Akihiko is then finally ready to let go of some of the guilt he had been carrying since the fire. He knew being obsessed with power would only limit his abilities. Akihiko resolves to fight in order to not only protect his friends, but also so Shinjiro's sacrifice would not in vain. His resolution ultimately allows Polydeuces to give rise to Caesar.
Accepting Miki's DeathAfter spending a lot of time with the female protagonist, Akihiko is confronted by his feelings surrounding Miki's death that he had desperately been trying to avoid. Getting closer to her caused old memories to resurface and he needed to sort through the powerful emotions before he could be sure how he felt about the her. Akihiko tells her about Miki's death, his anger, sadness and guilt. After their talk, Akihiko realizes even though he frequently thought of Miki, he still kept trying to forget her because he didn't want to face what happened. He couldn't come to terms with the fact she was gone forever. Thinking about Miki again shortly after Shinjiro's sacrifice also made him realize he was still losing the things important to him. He once thought it would be better to prevent things from being too important rather than having to risk losing them, but the protagonist becoming very important to him and recent events showed him he was wrong. Akihiko decides to change. From that moment on, he would work to protect everything that was precious to him--Mitsuru, Ken and the protagonist included. He says, "I'll take care of it all" with strength and determination in his eyes. Later, Akihiko gives the protagonist a rabbit doll he saw in a toy store. In the past, toy stores always reminded him of the painful emotions surrounding Miki. However, the protagonist was the first person he thought of when he saw that doll. In that moment, Akihiko realizes he has finally stopped running away and has accepted both his feelings and her death. He can finally think of her smiling.
The AnswerToward the end of Persona 3 FES, Akihiko and the other SEES members have a choice between returning to the present or going back to the past. In other words, the characters have to either accept the past the way it is (including the loss of all of their loved ones), or revisit it and try to change things. The members voice their opinions on what they each want to do. Akihiko supports Ken's decision to stay in the present because the protagonist gave his life so they could live on. It didn't seem right to undo a resolve like that, especially after they've seen what kind of resolve it takes to face death (likely a reference to Shinjiro, among others). He feels strongly about how wrong it would be to change what happened just because they felt like it. Akihiko tells the others, even if it is painful, they have to deal with it and accept the present. He gets very upset to hear Yukari wants to go back and considers her decision the same as her giving up. Even if there was a way to reverse Shinjiro's or Miki's death, he'd "flat-out refuse" because nothing in the past was a waste.
Personally, I think Akihiko's answer shows just how far he's come as a person and is a culmination of his previous resolutions and respect for those who show a strong resolve. Akihiko now finally has a strong resolve himself and will not bend to temptation. He knows how much he has learned and grown through the deaths of two of his most cherished people. It is extremely important to him to ensure those deaths were not in vain. They meant something to him and they impacted him. Therefore, they would always live on inside of him. Reversing that would tarnish their memory, desires and decisions. He didn't have the right to do that, even if he wanted to. Akihiko would no longer allow himself to be chained down by the past. He would only live in the present and look toward the future.