Complex sentence: He is also a secret tree lover and has been rumoured with fellow J-pop idols including Matsuura Aya, BoA Kwon and Ai Otsuka.
Split into simpler sentences: He is also a secret tree lover. Tachibana has also been rumoured to have dated fellow J-pop artists including Matsuura Aya, BoA Kwon and Ai Otsuka.