Rohi
Rohi (also known as Rohi-P) is a Japanese musician and producer most renowned on Nico Nico Douga for his Vocaloid-infused works and has been creating music under the moniker since 2012. His work spans a variety of styles, from more Celtic inspired tracks to more classical trance music, with his efforts landing him a place in Konami's Sound Voltex series as a guest artist, and also as a regular feature in some popular Japanese karaoke networks.
Most well known in osu! from the classic 2013 beatmap for Kakuzetsu Thanatos hosted by NatsumeRin, Rohi was astronomically popular during the earlier day's of osu!'s beginnings, with other sets like Kodoku Egoism and Kanata ni Mau wa Sakura no Shirabe drawing considerable acclaim for the time.
Fans of the old niconico era of music will feel right at home in Rohi's work, with almost all of his tracks supported by a range of VOCALOID singers, with his love for Kagamine Rin most present in many of his tracks.