[8] During US President Donald Trump's Fall 2017 trip to Asia, Kosaka was chosen to sing at the official state reception, reportedly due to Japanese Prime Minister Shinzō Abe's wish to keep the mood "upbeat".

[9] Kosaka is also known for portraying Muryou Hakataminami in Mashin Sentai Kiramager (2020–2021).

Daimaou Kosaka married Hitomi Yasueda, a gravure model, on 3 August 2017.

[10] On 17 June 2018, Yasueda gave birth to their first daughter[11]and, on 27 october 2020, their second[12] Kosaka portrays Muruyo Hakataminami (The owner of Carat, Mentor to the Kiramagers, and Younger Brother to Kiramei Silver) on Mashin Sentai Kiramager.

His role as Pikotaro (Most notably making PPAP) has been referenced many times, including (but not limited to): Footage of Kosaka's Pineapple Pen song was utilized in The Emoji Movie.