"Project A-ko" was initially planned to be part of the "Cream Lemon" series of pornographic OVAs, but during the production of the series, it was decided to make it into a more mainstream title. The only sequence animated during its "Cream Lemon" days left in the revised production is B-ko's private bath scene. In a nod to "Project A-ko's" origins as a "Cream Lemon" episode, the owner and several working girls from the brothel in the "Cream Lemon" episode "Pop Chaser" - where director Katsuhiko Nishijima was one of the animators - can be seen in one of the classrooms A-ko and B-ko crash through during a fight sequence in the film.