Nariyuki wins a smartphone in a lottery and he is ready to utilize all the features on his new phone, including the dictionary and calendar, for his studies. He also learns that studying during bath is effective and quickly puts the method into practice. Nariyuki subsequently becomes a fan of studying in the tub without any distractions and being able to easily look things up on his waterproof phone.
　But trouble ensues when he accidentally sends Fumino a message and calls Rizu. On top of that, Uruka picks up his call when she’s bathing and mistakenly switches to a video call...