In episode 6, there is a scene where Daiku, a former team member of Igo soccer, is getting bored with their inactivity in their club room. The conversation follows like this (read from left to right):
Daiku: Oh come on, everyone said they had cram school and left...
Daiku: And you're no fun, Sekiguchi
Sekiguchi is reading a book silently
Daiku: Don't you go to cram school, Sekiguchi?
Sekiguchi flips a page, looks at Daiku, then continues reading the book silently while being embarrassed
Daiku stares at Sekiguchi
Sekiguchi is getting more embarrassed
Daiku: You're joking!
Why was Daiku surprised all of sudden?
Relevant video on YouTube