Spacewalking With You 1

Kobayashi just can't focus—not on studying, not on work—and the adults in his life think he's in danger of becoming a worthless dropout. Then, one day, a strange new presence arrives in his class: an energetic and naive kid named Uno. Kobayashi saves Uno from getting scammed, and that close encounter launches a new friendship. Uno's definitely a space cadet, but Kobayashi can't help admiring the way he floats through life, and before he knows it, he might start feeling his feet lift off the ground, too…

Volume 1 of the Spacewalking With You manga series by Inuhiko Doronoda.