The boyfriend of Asumi who hates mathematics is Saki-chan, a teacher of mathematics. The condition of keeping it absolutely secret is always evaded and badly treated... Although she attempts his heart by using various means, she turned to like Saki-chan! Even if she loses sight of her own things, the things of Saki-chan will not be missed! Including the story of Saki-chan, the collection is full of hearts of an honest girl!