Name a case of the main heroine who happens to be the dumb muscle-type.

Orihime Inoue (Bleach)

she is also strong but totally dumb..........he he he h

I hope a 日本漫画 character is also allowed here

Tomo Chan from Tomo Chan is a girl

The exact definition for your 问题 🤣she was the first person who came to my mind