Despite her unassuming stature, Eri is one of the most powerful characters in My Hero Academia. Eri's Rewind quirk gives her the ability to revert anything back to its previous state. This powerful Quirk was exploited by the yakuza until she was rescued by the Pro-Heroes. Despite being one of the central figures of the Shie Hassaikai arc, very little is known about Eri and one of the greatest mysteries surrounding her is Eri's actual age.
Unlike most of the other characters in MHA, Eri's background is never explored in depth. In a flashback, we learn that her Quirk manifested suddenly and that she rewound her father back into nothingness in that incident. Apart from that, nothing else is known about her life before Overhaul. This enigmatic past makes it tricky to reduce her current age but it's not impossible.
How Old Is Eri When She Debuts In MHA?
Eri was first introduced as the "daughter" of Chisaki Kai during the Shie Hassaikai arc. She was abandoned by her mother, the daughter of the yakuza leader when her mutation Quirk manifested and left in her grandfather's care. That said, her tragic backstory didn't reveal her age right away but from her mannerisms and attitude, it was obvious that Eri was quite young.
Eri's grandfather entrusted her to Overhaul due to the apparent similarities of their Quirks and it's unconfirmed how long she remained in his care. The exact timeline for Eri's early years isn't clarified, but in Eri's character profile, it is revealed she was just 6 years old.
When Is Eri's Birthday?
Birthdays aren't celebrated with much fanfare in-universe in My Hero Academia, but, surprisingly, every character is given one in their profiles. Eri's birthday falls on Dec. 21, making her a Sagittarius. The exact year of her birth is never provided but that's not too surprising as MHA has never divulged the exact year the story itself is set in.
How Old Is Eri in 2022?
My Hero Academia's universe operates on a timeline independent of the real world; though the series has been running for close to eight years, all the events that have transpired since Midoriya Izuku first met All Might have happened in just over a year. Eri first debuted in Chapter 128 "Boy Meets...," which was released on Feb. 27, 2017. If she were to age like she would in the real world, Eri would turn 11 in 2022, but her in-universe age should be much younger.
Although Eri's current age hasn't been revealed, it should be easy to guess given the progression of events since she was rescued. It's fair to assume the raid on the Shie Hassaikai base occurred mid to late summer and Eri was 6 at the time. Quite a bit of time has passed since she was cleared to live freely within UA. Eri has been encouraged to socialize with the UA students, and on one occasion even joined Class 1-A for their Christmas party. Because Christmas occurs just a few days after her birthday on Dec. 21, we can conclude Eri had one more birthday after her rescue and is currently 7 years old in the story.
