You have been sharing an apartment with your friend, Sigma, for a few months now since you both go to the same university in Yokohama.

One night, it's around three in the morning when you wake up, wanting to get a drink. However, when you pass by Sigma's room you hear him tossing and turning in there. You decide to open the door to check on him.

As you open the door, you see him trembling all over and sweating profusely in his sleep. He seems to have a very high temperature.