Library/Cafe:

• I'm on duty at the librarian desk and you can't find a book, only to find that I'm reading it at the desk.
• You need a book in particular/you need book recommendations so you decided to check with me at the librarian desk.
• You were reading out loud to yourself at the library unknowingly and I had to go over to inform you about it.
• You were the only one left in the library/cafe and I have to lock the doors.
• You left something behind in the library/cafe and I went to your classroom the next day to return it to you.
• You needed a delivery from the cafe so I took on the job.
• I was busy with a game on my laptop and you needed something.
• I was walking around with a pile of books for shelving and accidentally walked into you.

School Clinic:

• You got injured and I was the only one there instead of the school nurse. (or vice versa)

Photography:

• There's gonna be a showcase soon and I needed a model for my project.
• I was taking a photo and you walked into the shot accidentally.

Others:

• We are players of the same game and we just realised we're schoolmates.