Asako Yaeshima and Kotaro Natori's scent-sual relationship is going well, though they've decided to keep it a secret from their coworkers for now. However, Kotaro's protégé, Korisu Ichise, can sense something's going on between the two of them... but what? And when Asako tells her family about her new beau, her brother decides Kotaro needs to be put to the test. Because a playboy like Kotaro must spell doom for his sister... right?