Big Sister is a Cleaner - S1.E1

Hara Sayuri is a student who lives alone in a cheap apartment. In order to earn money to pay the rent, she holds a number of part-time jobs. Today, she is washing the upper windows of a building. Coincidentally, she finds herself cleaning the windows of the office in which her elder brother is working. However, when she calls out to him, she sees him get an erection! Seeing that, Sayuri removes her clothes and proceeds to strike provocative poses...