I can't speak or write Japanese...Quite a shame..
This is a birthday present for myself.(Today is my birthday.XD)
Well,it's a concept art for a fanwork novel of TOUHOU,discribing the story of a large conflict between tengu and human(samurai,monk warrior maybe?I am fond of The Sengoku period.XD).
The tengu in the left is not Momiji,though.Because the story happened in a rather early time...(BUT I still add the TAG"Momiji",sorry for that.)