Circles: Busou Megami (武装女神)
Authors: Kannaduki Kanna (神無月かんな)
Parodies: Sengoku Basara / 戦国BASARA
Pages: 20
Released: 2009-07-17
Language: Japanese

https://www.doujinshi.org/book/230048/

Huh, this has been out a long time. Good to see someone finally pick it up. The more Kasuga the better.

So, for those who can't tell, at the end she basically causes his cum to flow back into his body and cause retrograde ejaculation (cumming into his own bladder), which given the era is quite a deadly occurrence. That's apparently a technique that kunoichi supposedly know how to do, reversing the flow of cum to inflate a man to death and all that. Given it doesn't seem to be intended to be arousing but a way for Kasuga to carry out her mission and escape, I don't know if that should be tagged or not, but I'll leave that to you all.

Also for those who care, the fat guy is evidently Ujiie Bokuzen. Not an actual character in the series, but he is a historical figure.

Base +6, Red of EHCOVE +53, DEMECRIO +7