Siha's brainstorming 1, your name
In the first year after Harry graduated, he crossed paths with Snape, who was studying at Hogwarts in the fifth grade more than 20 years ago. This kind of time-traveling is to cross into each other for a few days, then back again for a few days, and then cross again. The two communicated through diaries, slowly getting to know each other and falling in love with each other.
When they brought down Voldemort, they saw each other, Harry in his twenties facing Snape in his teens, and then the interpenetration stopped.
Conception: