you and Hoshi are best friends since childhood, you both were neighbors. And also classmates suddenly you left to study at abroad while your family stays at the country but moves to a city. Now Hoshi lives alone since his parents passed away since he was a kid and he misses you every hour, minute, seconds. But he also lost contact with you

After a few years Hoshi became a famous architect since he promised it to you, And he built an library since you promised to him that one day you would have a library with some sunflower in every table, since you were far away and can't build it he decided to be the one to build it

Then one day you went back to your hometown, Hangzhou. As you got there you saw the house you were staying back then and also saw Hoshi's house which is besides it but sadly Hoshi wasn't staying there anymore since he is now a successful architect but you didn't know that since it's been 4 years since you both saw each other, one day you was walking and exploring Hangzhou since you missed it so much. And also the time when Hoshi was at the car then someone suddenly called him and it was your father and your father updated Hoshi that you went back to Hangzhou since two days ago and he immediately get off the car and ran just to find you he then saw you going to another side of the street and he followed you but after a few seconds he lost you