The "My Happy Marriage" anime series, based on the series with over 10 million copies in circulation, is set to air a "Special Edition" in 2026. Following "Anata no Soba ni." for the first season and "Shiawasena Yakusoku." for the second season, Riria. will perform the opening theme song for a third consecutive installment, a first in the history of the series. To commemorate the broadcast of this Special Edition, "Watashi no Shiawase na Kekkon EP" will be released. In addition to the three opening theme songs to date, it is scheduled to include acoustic versions that offer another way to appreciate the songs, as well as a special voice-cast vocal version sung by the protagonist Miyo Saimori [CV: Reina Ueda] (subject to change). Backed by the series' immense popularity, this commemorative EP looks back on the history of the series and is an essential item for "My Happy Marriage" fans.