Kunoichi No Ichi! Vol. 4

While on a school field trip to a ninja estate, high schooler Ichi gets pulled into a mysterious mechanism that pulls him back to the age of ninja in Kunoichi no Ichi! In hopes of finding a way home, he tries to infiltrate the ninja-training Kurenai Academy, but it turns out to be a no-boys-allowed academy for kunoichi!
After an attack by a kunoichi group attempting to take back certain materials, Ichi is forced to leave Kurenai Academy after it’s been revealed to Ayame and the others that he’s a boy. Kunoichi Kosaki’s evil hand then creeps up on Ichi in Vol. 4~
Notice: This manga is written in Japanese.