Honoka ni Purple(1985)

Honoka ni Purple

There's a legend about a certain library at the Doumeikan University, and whoever meets there for the first time will fall in love. One fateful day, Shino waits for her date there, but she doesn't meet him. Instead she meets a football player who took refuge there, trying to avoid his angry teammates. Then the two surprisingly find out that their parents are getting married, and so they start to live together...

(Source: Shogakukan, translated)