Subsequently, along the section of the Kyoto side there was a plan to open the line with underground tracks, but the plan was changed in order to hastily construct a provisional terminal station at Saiin in order to meet the state-funded Enthronement Ceremony of Emperor Showa, and in 1928 the entire section of the line between Tenjinbashi Station and Saiin Station became fully operational.
その後、京都側は地下線で開業させる予定であったが昭和天皇の即位大典に間に合わせるため、急遽西院に仮のターミナル駅を設けることにし、1928年に天神橋～西院間の全線が開業した。