
I don't know if this is right but do you think maybe Sangwoo thought Bum was in the wardrobe and told the officer to look so he could just kill him? 'Cause the knife was gone from the counter and I just thought maybe Sangwoo was going to kill the officer when he saw Bum in the wardrobe. I am probably wrong... I just wanna know where the knife went.

This is my perspective so I'm not so sure.... Sangwoo thought that Bum is in the basement (you know how the wardrobe has secret entrance to the basement) that is why he ask the police officer to check in the wardrobe since the police officer is very suspicious of it. The knife was missing because Sangwoo hide it from his back, you actually see Sangwoo reach for his back when the police officer about to open the wardrobe. He basically plan to kill him just in case Bum was still in the wardrobe but fortunately Bum wasn't there><
So this was a looooong time ago but in the beginning chapters, we saw them as adults. Zheng xi asks Jian yi where he was during highschool because he supposedly disappeared. So I thought the whole time we were looking back at the past leading up to them going to high school. Or was all of the beginning just not canon?
I’m really confused too, but after re-reading those parts I think that they’re in middle school rn and going to highschool idk aha
Here's how it is:
The first 50 chapters or so are what you called the 'beginning chapters', where there's random scenes and it also shows them "in the present" - university level. That is Xi is in uni, while Jian Yi has to go back to high school and asks Xi for help with studying so he can go to the same uni as Xi. That is soon after their reunion and then Xi asks where the fuck Jian Yi was all this time and Jian Yi starts to talk, Xi doesn't believe him and then..
..we're in the retrospection mode. Last year of middle school, near the end of the year as far as I recall. From before this retrospection began, we know Jian Yi gets "kidnapped" on the second day of high school and appears back only as we saw at the beginning. So, now, the whole manga since chap. 50-something is taking place across a few weeks, near the end of their middle school and as their relationship develops, we are constantly getting closer to that day Jian Yi is disappears.