Harukanaru Toki no Naka de 6 Gaiden ~Tasogare no Kamen~ (遙かなる時空の中で6 外伝 〜黄昏ノ仮面〜) was an Engeki Joshibu musical starring Tsubaki Factory. It is an adaptation of the sixth installment in the Harukanaru Toki no Naka de otome adventure game series which was released for the PlayStation Portable and PlayStation Vita in 2015. The musical ran from June 6 to June 23, 2019 at Ikebukuro Sunshine Theater in Tokyo and Hotel Mielparque in Osaka.