Type-moon, I Raised Beast in the Otherworld

Sajō Chisei was transported to the Type-Moon universe, becoming the adopted son of the Sajō family and having two younger sisters…Sajō Ayaka and Sajō Ayaka. At sixteen, he awakened an ability: the power to travel to another world. In the present world, he attends the Clock Tower, a struggling magic student whose academic record is on the verge of collapse. But in the other world, he experiences a series of extraordinary lives. During the Tunguska explosion, he adopted a fox and named it 'Koyanskaya'. In Britain, he was Morgan le Fay's adopted son, witnessing the tragedy of sisters turning against each other. In Uruk, he had a loving mother named Tiamat… Finally, one day, followed by the Seven Beasts, Sajō Chisei arrived at the gates of Chaldea and said to the bewildered doctor and others, "Doctor, I've come to help you save humanity!" Mash: What are those behind you?! Sajō Chisei replied sincerely, "They're my Pokémon." "You were supposed to save humanity? Who told you to conquer the Beasts?!"