Ikematsu who transforms into Ozaki in the movie, also had to sing his famous hits. He commented although he had never met Ozaki in person, he felt as if the latter was always near him due to the influence of his music which has lasted till this day. As such, he felt that it would be worthwhile to explore the theme of what it means to love with the director even though the answer to this question would probably be unknown or unclear even if one has loved many times.
Mitsushima who had to play Pitt with his broken English, said that he had a lot of faith in the power of this original story especially since he got to work with such a strong cast and staff. As such, he hoped that the passion they experienced during the summer when they filmed the movie could be conveyed to as many people as possible.
Ookura who had to play Sakamoto, admitted that he was unsure about how to approach his role even after going through the script reading session. However, through his discussions with the director and co-stars as well as going through rehearsals, he was able to dive into his role without reservations.
Sources: Eiga.com / Natalie