Lemme guess: Trainer had a date and Suzuka decided to "accompany" him?
Pretty much.
...Well, she originally decided to be the bigger woman and let her trainer go, but then she accidentally glanced at the flirty messages he was receiving so she did a complete 180.
Omanyte doesn't have a domino mask at all even as a Pokémon. It's absolutely inspired by Splatoon- the ears are a hint as well. On the next page, Omnastar's "teeth" are also based on Inkling "teeth", so it's safe to say Kinkymation had Splatoon on the brain when making these two.
It's heartwarming to see a Les Chevaliers Du Ciel artwork this far along the century. That movie single-handedly made me fall in love with flying in general.
