@Shadedhoneybee for as i remember, he wants to help and teach the kids in poor countries (his penmate d/ied of malnutrition when he was just a kid). he wants to travel around the world to find kids in need with that senpai of his and help them. i also remember him saying that it is something he wants to do himself (as in like, alone) so maybe that's why yuki is not thinking of going with him.