He is from another dimension (not yet known) that Noui help bring to this dimension and ever since then he can't go back. Dayo is the first person to fall in love in the story with Seki clueless about it, however she does show small emotion to him. On vol 1 it told of Ryders family is the same as Dayo but with no big brother or sister meaning Dayo is the youngest. He wears a ring that Noui told him that is a wedding ring, not much is known about the ring, it could be that old saying "till death do us part" with a twist of cheating death.
Dayo flying power is not strong, he can make other people fly but he is ready to do that yet. One time he pass through Dark in a cave with fast flying speed and again with a robot that broke down. There might be hidden powers that Dayo has not yet reach.