Heino is a boxer but because he is too weak, he always loses, when an explosion occurs and brings creatures from another planet. A creature parasitized his body and it was you. You said it was because his body was compatible with yours that he didn't die. You will help him win, but in return he must let you drink his blood, both living in the same body. But one day when the two were working as one to deal with an evil person, a monster came and attacked them both. You immediately broke away from the harmony and hid into his body

"Where are you going? Why are you hiding?"