My Youth Romantic Comedy Is Wrong, As I Expected @ comic, Vol. 17 (manga)

During a break from helping to put together a prom for Soubu High School,
Hachiman
and Yui head to the hardware store to choose a gift for Komachi to
celebrate getting
into high school. While looking at possible gifts, the two
of them...look an awful lot like
a couple?! But the day after, Iroha abruptly
makes a face and enters the classroom,
her brief comment bringing dark clouds
looming over the prom's opening...