Rainbow Corps Robin: vol.1 (1995)
Rainbow Sentai Robin (Rainbow Corps Robin) is a 1966 Japanese anime series created by Shotaro Ishinomori about a half-human, half-alien boy who leads a team of six unique robots to protect Earth from alien invaders.
A distant planet, far off in space named Palta is facing the doom of extinction. There are only two years left until their ultimate demise. Palta looks to Earth to cultivate resources and begins attacking it in hopes of taking over. Earth turns to a boy named Robin, who owns many robots.
No obi.