During the preparations for the stage play, Yamamoto wrote a total of 40 letters to Horikita but she did not replay to any of them. In the end, Yamamoto decided to give his contact details to her instead of waiting for her to give him hers before the end of their stage play's run. He thought that everything was over by then but was pleasantly surprised when he finally received a message via LINE from Horikita. However, there was no way for him to meet her directly even though he was deeply encouraged by her first response in six years. Just then, Yamamoto got wind of news that Horikita was heading to Kyoto for work and on the spur of the moment, bought a Shinkansen ticket to Kyoto just to try his luck. He thought then that if he managed to meet Horikita on that same train, it must be a sign that they were meant to be. Fortunately for him, he did meet Horikita on that same train and proposed to her with a ring that he had prepared in advance despite the fact that they had not even started dating. As such, strictly speaking, the couple did not date for a single day and got together with the intention of getting married.
At the time when "Arashigaoka" was being performed in May, there were indeed rumours in the media of Yamamoto expressing his interest in Horikita but she had brushed him off. Especially when Horikita's reputation of being a tough nut to crack in the romance department and how unhappy and critical she was said to have been when her colleague in the same agency Kuroki Meisa got into a dekichatta kekkon with Akanishi Jin, her acceptance of Yamamoto came as a big surprise to everyone. Yamamoto had a fairly long string of romances with other female celebrities such as Matsu Takako and Suzanne in the past.
Soon after the proposal on the Shinkansen train, the couple began living together early this month. 5 days before they submitted their marriage application, Yamamoto wrote another letter to Horikita to ask for her hand and she finally replied for the first time in the affirmative.
Yamamoto commented that during the interview that he never expected his one-sided love to be requited one day and finally felt like reality sinking in when he sees his wife at home now.
Source: Nikkansports / Sanspo / Sponichi