Since the title you mentioned refers to a specific series, "helpful" could mean a few different things.2?
Instead of a kiss, Rin does something far more intimate: she fixes his crooked glasses (a callback to Chapter 1, where she called him "four-eyes" mockingly). Then she says: Since the title you mentioned refers to a
The chapter ends with a masterstroke. The rain stops. As they leave the shrine, a group of Rin’s university friends spots them. One of them yells, "Oh! Is that your 'little brother' you’re always gushing about?" Since the title you mentioned refers to a