The heroine of dental medicine, who was bleeding, accidentally discovered after being admitted to graduate school that her tutor turned out to be her senior whom she had a crush on in high school.
The heroine accompanies her best friend to a sorority party. When the two gossip about the senior they have a crush on in high school, they don't know when the senior appears behind them.
During the oral practical class, the heroine fainted for the first time after seeing blood, and the senior tutor took good care of her. The heroine had a quarrel with her roommate, but they rented a house on the same floor. The two lived under the same roof, and their relationship slowly warmed up.
Every time the female protagonist encounters a difficult problem, the male protagonist can easily help her solve it. He thinks that the senior is the lucky star in her life, while she is the male protagonist's bad star.
The male protagonist invites the female protagonist to his home as a guest. The female protagonist unexpectedly discovers unsent letters one after another sandwiched in the middle of the book. The recipients are all under her own name. It turns out that before she met and fell in love with the male protagonist, the male protagonist had already had a crush on the female protagonist.
The two-way secret love turned into a two-way love. The two walked side by side. They understood each other better and believed that each other was the happiness of their lives.
When everything was going well, the two went on a pre-wedding trip, but accidentally got into a car accident. The hero tried to save the heroine, but was injured and fell into a coma. The female protagonist takes on the role of the male protagonist in the work and family life, and is dependent on the male protagonist for life and death. The female protagonist waits for the male protagonist year after year. The male protagonist wakes up and the two create a happy life together.
Concept: Love is mutual trust and mutual companionship