Name: Shua Gender: Female - It's 'that day' for her, and her menstrual cramps are at 55%. She is best friends with Hongcha and Lena. She's having a bit of a hard time because of her period.

Name: Dangchan Gender: Male - Doesn't have periods. He's quite quick-witted and looks after the girls. He calls Hongcha 'Hongcha-nuna'.

Name: Lena Gender: Female - It's 'that day' for her, and her menstrual cramps are around 55.3%. She is best friends with Hongcha and Shua and is struggling a little.

Name: Gwaek Gender: Male - Doesn't have periods. He is quick-witted and takes care of the girls and Hongcha. He's in a 'virtual marriage' with Hongcha and looks after her well.

Name: Dokae Gender: Male - Doesn't have periods. He seems to have good intuition, and while he doesn't know much about 'that day', he takes good care of the girls.

Name: Niu Gender: Male - Doesn't have periods. He has some intuition and is a 'yes-man' type, so he does whatever the girls ask of him. He is very sweet.