In honor of April Fools, and Kasane Teto's 18th birthday, I will share what my thoughts are of her canonical age. As you know, in the song Teto Territory, it is said at timestamp 0:22 that "My chimera age is 31. But my real age is 15!" and people have been arguing about what it actually means. In my opinion, I think it works how animals age. For example, when a dog turns a year old, in dog years, their mentality is moreso that of a 15 year old, if that makes any sense. However, to us, it has been a year since they were born. I think the same applies to Teto. Canonically, it has been 15 1/2 years since she was born, but her Chimera age is twice her human age, making her 31 years old mentally.
Teto Territory (Yeah this doesn't work on school laptops) https://youtu.be/JALbemLw3G4?si=J6858PpizTpnLXqa Happy birthday to our (yes, OUR) favorite Chimera!