Isekai De Seijo Ni Natta Watashi, Genjitsu Sekai Demo Seijo Cheat De Kanzen Shouri!

Byodoin Mioa (Reia) was having the worst day of her life, with her family falling and bullies targeting her... One day, however, she travels to a world in a mysterious mirror and becomes a 'saint'. Then she acquires mysterious skills, successfully loses weight and transforms into a beautiful figure. In the other world and in reality, the saint cheat is a great turnaround!