The story line is relatively simple. The protagonist, Rui is a teenage girl. One night her father brings home a co-worker Mr. Igarashi. Rui is quite smitten with Mr. Igarashi and tells her father that she is interesting in learning about statistics so that she can be tutored by Mr. Igarashi. The day of her first lesson, her tutor shows up and it is not who she expects. Rather than her heart-throb