Pureji Oshou

The cute bird he bought from the pet store was actually a distinguished sage who reincarnated from another world. Bestowed the opportunity to cross between worlds and immense magical power, he decides to use it to live a comfortable life, selling things from his world, training his magic, and eating delicious food. However, he discovers beings with special abilities in present-day Japan. A story where a corporate slave, who was at a deadlock in his career, gets wrapped up in a battle of special powers and cuts it close with his magic as he travels to and from the other world and present-day Japan. Magical girl included. Source: Mangaupdates

A "demon school" established in the demon world for an upcoming rematch with the human race. The days of fighting demons' friendship, food, and muscle training! Pre-serialization

Isei’s life crumbled right before his eyes as the one he fell in love with died. But when everything seems dark in his life something happens…