Board Thread:Questions and answers/@comment-30069821-20161031231921/@comment-8695373-20161102183510

Murakumos do age, look at Noel. Naoto is a normal human, Ragna is an artificial human, but nothing indicates that his lifespan was supposed to be longer. Hazama ages, since his body should be similar to Kazuma's, and if that guy wouldn't age at all during his 8 years at Ishana, everyone would notice that. Also in BE "Hazama" looks like he's the same age as Naoto. Hakumen is Jin + 90 years, but his body doesn't age since it is just an armor that housed his soul.

Jin has to be around 22, and Mai, Tsubaki, Makoto, Kajun and Shiori should be around 19, going by Japanese high school theory.

It is impossible to tell Amane's age by his appearance, according to Bullet, he hasn't aged at all since their last meeting ten years ago.