In Horikita's statement, she mentioned that she and Yamamoto first met about 6 years ago through work but only became attracted to him after working on the stage play "Arashigaoka" where she got to know him better. As such, this was what led to them getting married eventually. She ended her statement by asking for everyone's support as they begin life as a married couple.
Meanwhile, in Yamamoto's statement, he revealed that they had submitted their marriage application on 22 August which he saw as a necessary step to fulfill the responsibilities needed of a man. He mentioned that he met Horikita while filming the 2009 drama "Atashinchi no Danshi" but it took them about 6 years before they reunited in the play this May which led to the start of their relationship. Yamamoto asked everyone around them and Horikita's fans to continue supporting them as the two of them embark on a new phase of life hand-in-hand.
Source: Huffington Post Japan / Oricon / Nikkansports