itsu is a series of Fairy monsters based on characters from Sexy Parodius, a Konami game that parodies Gradius. When translated, the names "Koitsu", "Soitsu", "Aitsu" and "Doitsu" mean "This Guy", "That Guy", "That Other Guy" and "Which Guy?" respectively. The names are whimsical and not meant to be taken literally. To keep the flavor, a more appropriate translation might be "Eeney", "Meeney", "Miney" and "Moe".