Persona
Most, if not all of the Persona in
Persona 3 are based on folklore and mythology. Akihiko's two Persona are no exception. The rest of this section will explore the stories behind
Polydeuces and
Caesar and how they relate to Akihiko's character.
Polydeuces

In Greek and Roman mythology, Polydeuces (Pollux) is the twin brother of Castor. Both brothers are considered to be patrons of horses, however Polydeuces was more of a skilled boxer. Stories depict Polydeuces and Castor always being together. While there are variations of the their tale, the ending is typically agreed upon. While in the midst of battle, Castor is impaled by a spear right in front of Polydeuces' eyes. Polydeuces is a God and is thus immortal but his brother is not. Completely devastated by his brother's death, Polydeuces offers to go to Hades with his brother or share some of his immortality so they could still remain together. Zeus, however, chooses a third option. He puts the two brothers in the heavens where they become the major stars in the constellation Gemini.
Clearly the story of Polydeuces and Castor parallels with Akihiko and Shinjiro (Castor is Shinjiro's Persona). The two are not brothers by blood, but their relationship is so strong that they are described as being like brothers. Before Shinjiro's accident, they were inseparable. Shinjiro only joined SEES because he refused to let Akihiko be alone. Akihiko wouldn't take Shinjiro leaving as a permanent answer and consistently asks him to come back because he wants to be with him. Like Polydeuces, Akihiko is also a talented boxer. Akihiko experiences the same tragedy of seeing his beloved brother killed right before his eyes and grieves terribly. While Akihiko is clearly not immortal, Shinjiro's death while he lives on could still be representative of the story of Polydeuces and Castor.
In Persona 3: Official Design Works the designer comments that Polydeuces is a Spartan hero who is said to excel at boxing and can rival an entire army by himself. He is also said to be immortal because he has the blood of Zeus. It would seem, then, Akihiko's first Persona was definitely designed after the myth.
Caesar

Once Akihiko gains his
resolve to fight, Polydeuces gives rise to Caesar. The designer comments that the concept for Caesar is actually
not referencing the famous Roman emperor Julius Caesar personally. Rather, the name was meant to have the meaning of being of brave, noble and superior character. "Caesar" eventually became an imperial title in Ancient Rome and was used to reference the Roman emperors. I feel the character traits the designer mentions actually fit nicely with Akihiko's resolve and growth as a character. Akihiko is certainly brave to be able to witness his best friend's death/coma and pull himself together to face more hurdles ahead. It would be much easier to wallow in guilt and grief than to take those feelings and use them as motivation to continue forward. Having a solid reason to fight could arguably make Akihiko feel more brave in the face of dangerous situations as well. I think Akihiko has been a noble character from the beginning in regards to refusing to leave anyone behind or let anyone get hurt. However, after he comes to terms with Shinjiro's death/coma, his motivation to protect others stems less from guilt and more from a higher personal quality of caring. I would say Akihiko is a character who upholds the title "Caesar" well in the modern world.
RESOURCES:
Castor & Pollux @ Myths Encyclopedia
Caesar (title) @ Wikipedia
b a c k . c l e a r . f o r w a r d Resonance is © Samantha, however Akihiko, Mitsuru and Persona 3 are © Atlus and other rightful owners. Resonance is a part of AFTER-DEATH.ORG.