After partaking in a challenge between the Deviluke sisters to see who can withstand cold temperatures the longest, Lala Satalin Deviluke falls sick due to her unwillingness to give up. Worried about her wellbeing, Rito Yuuki decides to go to her room to check up on her. However, when he accidentally steps on one of her peculiar inventions, he inadvertently transforms into a thermometer, causing the situation to turn quite steamy...

(Source: MAL Rewrite)