If you're looking for anime similar to Project Piplup: It'll Be Fine!, you might like these titles.
The official music video for Natsu no Uta from the album 獄至十五, by Uchikubi Gokumon Doukoukai.
The official music video for Penguin Paradise by Ryuusei Nakao and Voiceland Kids that was featured on NHK's Minna no Uta program.