>>43464139background seems to say "okaeri nasai" which is pretty much "welcome back"
google translate only on the rest
seems it's just "congratulations" on the cake there
May's sign appears to be something to the effect of "surprising camo" so either this is "shh i'm gonna jump out and surprise her," a caption of "surprise party," "wow she's got a lot of different appearances," or perhaps it's just "the year is 2020. i am surprisingly forgotten"
I don't know much slang so yeah don't ask me what dokkiri kamō means outside of the literal translation I'm getting
TLDR may talking about some kind of surprise and some kind of camouflage
