OVA bundled with the special edition of manga volume 3. Morita Mayu is a high school girl. She is extremely reticent and her silence and habit of looking at people's eyes straightly sometimes cause misunderstanding. The reason behind it is not because she doesn’t like to talk nor because she has nothing to say. The reason she rarely speaks is due to the fact she thinks too much before speaking, thus losing the timing to speak altogether. Despite this, she lives a happy school life with her classmates.

Ginya Otonashi is a college dropout who works part-time for a pachislot publishing company while aspiring to become a novelist. One day, Ginya comes across a secret organization and gets pulled into a competition to become #1 in "Pachi Battle," which is all a part of the Slotseum, a pachislot competition.

Tadashi Matsushita has recently entered the Kansai Fifth Technical High School and joined its notorious karate club. There he meets his captain, Yoshiyuki Takagi, an incredibly strong individual. Feared and respected throughout Osaka, Takagi is deep down an honorable and compassionate guy despite his violent endeavors.

The second Ocha-ken series features the Tea Dogs interacting with humans.