You can answer those question but you will left some doubts.
1. How you know where she was supposed to go (Assuming he walk her to a metro station 'cause we never saw her house before the previous chapter) HARDEST ONE
I was so concentrated in the conversation that I even think about it, as she always takes the metro after cram, I just walk automatically as she never say something Ireally didn't thought about it.
2. You just join the club
Honestly I like her and want to confess, but when I found out she was going to be in a camp with all those guys I was afraid something might happen (like how I found you guys), I know is creepy but I was afraid of losing her with out been able to confess.
3. Why you were there (bridge)
I left the cram school and walk my way...
A. ( In case bridge is not his route) when I saw the bridge I remember the incident with the hooded guy(ch.1) when I saw someone standing on the edge.
B. It's my damn normal way to home, you morons