Just stating for the record that the above user attempted to change the tags on this post twice now. I reverted them because I see no clear evidence for flat chest, but I do see a slight curve in Chino's chest that seem indicative of small breasts.
Furthermore, this user has a history of not paying attention to details and recklessly replacing small breasts with flat chest when it's not appropriate (see post #8649944, post #2625469, and post #9782159 to name a few), so I don't trust their judgment on more contentious posts like these. If another user with more experience thinks Chino qualifies for flat chest here and can give a good explanation why, I'm okay with it being changed back.