Yamada who is acting in a movie as the lead character for the first time, commented that he had always wanted to work with Suda because of his great acting skills so he's full of respect for him in this respect. On the other hand, he unexpectedly found out that Suda is a strange person who behaves in a weird manner. Shiina also chipped in by saying that they had a meal gathering involving 70 people on the set once but Suda brought a guitar along not with the intention of performing for them and instead kept singing a meaningless phrase repeatedly during the gathering. In response, Suda said that there was a meaning in what he had sung but apparently, those around him didn't understand it. The cast also expressed great joy in seeing the movie being screened nationwide so that those in their hometowns could also watch the movie along with everyone else. Shiina revealed during the event that Director Hasumi's child was also born in the same morning as the first-day-screening which was a miracle because the due date was not supposed to be so early.
During the event, the lights in the theatre were suddenly turned off. When the lights were back on, the cast and audience were surprised to see Arashi's Ninomiya Kazunari on stage. His guest appearance was kept a secret from everyone including his identity as the voice actor behind Koro-sensei. Ninomiya revealed that he was offered the role of voicing Koro-sensei in autumn last year after the cast had finished the filming. He was told to keep it a secret including from Yamada who is his junior from Johnny's Jimusho and worried about when he might unwittingly let the cat out of the bag since he often met up with the latter. Yamada also revealed that his parents were convinced that the voice actor behind Koro-sensei should be Ninomiya but he was insistent that they had got it wrong because he didn't think that he would be kept in the dark as the lead if Ninomiya was indeed the voice actor. As such, Yamada apologised for doubting his parents and stressed that he did not lie to them because he was truly unaware.
Source: Eiga.com 1 / Eiga.com 2