I used this when my child was 6 months old. I kept it because I couldn't bear to throw it away, but I'll give it away now since they'll definitely never wear it again. The back has Velcro, making it easy to put on. It's very cute. I think a child whose name includes "Hiro" could use it right away. Hiroki, Hiromi, Hiroshi, Hiroto, etc. I think it can be used by both boys and girls. There are no stains, but please understand that I am a private seller, so I may have missed something. Thank you.