The sun in first panel is a reference to Hareyaka Sukoyaka Pikarinrin♪ ("Sunny Bright Pikarinrin♪" in EN server) by Hello, Happy World!. It even has "Pikarinrin♪" next to it.
Why is it so hot!?Pareo! Do something!FNIs this okay? Chu2-sama!Chu2-sama?EndPikarinrin♪