I parasitized it and raised its level, but it seems like it may have grown too much.

Caught up in a ritual performed by an otherworldly god, Eiji Torikai finds himself transported to another world.

Upon his transfer, the otherworldly god who performed the ritual attempts to draw out classes—the embodiment of Eiji's potential—but while there would normally be dozens of classes, Eiji only possessed a single class: Parasite.

With no other choice, Eiji, heading to the other world with only that single class, was initially disheartened, but as he begins to use its power, he uncovers its true worth.

Utilizing the Parasite's ability to multiply and claim the powers others acquire, Eiji's level may just soar past all limits.

Addendum: This has been published as a book by KADOKAWA BOOKS.