SirMillion

SirMillion is the family ship between Mirio Togata and Mirai Sasaki from the My Hero Academia fandom.

Canon
Mirio is an intern working under Mirai at the Nighteye Agency. Mirai initially took on Mirio because he saw a potential for greatness in him. Since then, he has been attempting to train Mirio to be the next holder of One For All. However, his plans do not come to fruition as Toshinori Yagi chooses Izuku Midoriya as his successor instead. Mirai holds resentment for Izuku, believing that he is not as worthy of the power as Mirio would have been. After Izuku and Mirio encounter Overhaul and Eri, Mirio holds a sense of regret for not saving the young girl. Mirai senses this, and tries his best to encourage Mirio. He tells Mirio that together the Raid team will rescue Eri. During the Shie Hassaiki raid, Mirio runs off ahead to challenge Overhaul. By the time Mirai catches up with him, he is surprised to see that Mirio has been holding his all against the organization head. He praises Mirio's hardwork. When Overhaul reveals that Mirio's Quirk has been erased, Mirai is shocked. He decides to do everything he can to protect Mirio from Overhaul, but is fatally wounded in the process.

On his deathbed, Mirai uses his Quirk one final time to see Mirio's future. Despite having lost his Quirk during the Shie Hassaikai raid, Mirai tells Mirio that he will become a great hero one day. He likely saw into the future were Eri uses her own Quirk, Rewind, to return Mirio's body to a state prior to losing his Quirk. Mirio begs him to hold on and to survive a little longer so that he can keep learning from him.

Mirai eventually dies with a smile on his face, knowing that Mirio will have a good future.

Fanon
SirMillion is popular platonic relationship in the fandom, although it can be a divisive one as well. Fans of the relationship between Mirio and Mirai see Mirai as a father figure for Mirio. They like the care and love that Mirai seemed to show for his mentee, and the ways in which Mirio grew stronger under his tutelage. They also love the final moments between the two, wherein Mirai used his Quirk to see that Mirio still had a promising future as a hero.

Others, however, believe that Mirai only cared for Mirio because he reminded him so much of All Might. These fans believe that Mirai didn't actually care for Mirio as a person and only saw him as a potential vessel; something Mirai himself admitted on his deathbed. These fans typically believe that Mirio deserved a better mentor, and care very little for the relationship between the two as they believe it is fake on Mirai's part.

Regardless, the SirMillion dynamic is important to Mirio's character growth. Many fans like to think that Mirio will take over the Nighteye Agency upon graduation, as a thanks to his late mentor. Many fics like to capitalize on Mirio's feelings after the loss of Mirai, and show who he copes with losing his mentor. On AO3, there are currently over 90 fics for this pairing. The romantic version has over 15 fics, and is much less popular in comparison.

Fandom

 * FAN FICTION