The demon Jashin-chan has been summoned to Earth by Yurine Hanazono, a girl with a knack for the occult. Unfortunately, Yurine does not actually know how to send Jashin-chan back to Hell. Now stuck on Earth, she must live at Yurine's apartment as her familiar. The only way for Jashin-chan to return would be to kill her summoner, but this is easier said than done for the incompetent demon. Since Jashin-chan is immortal and can regenerate her body, Yurine does not hold back in attacking her with a range of weapons, punishing her in gruesome manners for her evil schemes. Jashin-chan is also often visited by her demon friends: the kindhearted Gorgon Medusa and the energetic minotaur Minosu, who seem much more well-behaved in contrast, and disapprove of her plans to kill Yurine. Jashin-chan Dropkick is a comedy focusing on these two reluctant roommates and their bizarre antics as they get by with their cat-and-mouse relationship.

It is widely believed that science can provide rational explanations for the countless phenomena of our universe. However, there are many aspects of our existence that science has not yet found a solution to and cannot decipher with numbers. The most notorious of these is the concept of love. While it may seem impossible to apply scientific theory to such an intricate and complex emotion, a daring pair of quick-witted Saitama University scientists aim to take on the challenge. One day the bold and beautiful Ayame Himuro outwardly declares that she is in love with Shinya Yukimura, her fellow logical and level-headed scientist. Acknowledging his own lack of experience with romance, Yukimura questions what factors constitute love in the first place and whether he is in love with Himuro or not. Both clueless in the dealings of love, the pair begin to conduct detailed experiments on one another to test the human characteristics that indicate love and discern whether they demonstrate these traits toward each other. As Himuro and Yukimura begin their intimate analysis, can the two scientists successfully apply scientific theory, with the help of their friends, to quantify the feelings they express for one another?