Hoshino is a popular singer-songwriter and his last single "SUN" released in May this year achieved a No.2 ranking on the Oricon charts. He suspended his work from December 2012 onwards due to a subarachnoid haemorrhage and made a comeback in June the following year while still undergoing treatment. He is currently acting in the TBS Autumn 2015 drama "Kounodori" where he plays the rival of the lead played by Ayano Go. On the other hand, Nikaido is known for her acting skills and has garnered many acting awards despite her young age. She is also a student of Keio University while juggling her acting work.
With regard to reports on their relationship, Hoshino's agency commented that this is his private matter so they have no idea as to whether this is true. On the other hand, Nikaido's agency claimed that Hoshino is a good friend of hers but did not confirm nor deny the news.
Source: Nikkansports / Oricon