Mafuyu is gay (he never showed any attraction towards women). Ritsuka is probably demisexu...

Mafuyu is gay (he never showed any attraction towards women). Ritsuka is probably demisexual or even pansexual (we never really see him being attracted to anyone else before, man or woman, but who knows). Aki is bisexual (he's been with both men & women). Haruki is either gay or bisexual (not much known about his past attractions/relationships). Ugetsu is so far gay, with the upcoming chapters unknown, because no chapter or spoilers has been officially released, the rumours are just rumours.
That's all.