The labels have the character's name followed by 受 (uke), which means being the receptive or passive partner, or in BL slang means the bottom. Most underrated organizational system ever by the way. Please show this to anyone who claims that "unwoke" Japan doesn't "shoehorn queerness into everything".
I guess by in the middle I just mean not exclusively attracted to masculine or feminine attributes, speaking in terms of like more superficial physical attraction and not so much about romantic attraction and how that can be affected by gendered cultural norms and that sort of thing
Sexuality definitely is hard to pin down, it's like, all abstractions upon abstractions, it's so complex really that identifying "objective" information about it is basically absurd- basically trying to describe a thought or emotion by listing out neuron states or something, it's not possible