The entirety of 555; all its episodes and movies, were written by the head writer alone, Toshiki Inoue. This feat of writing every episode would not be repeated in a Super Hero Time production until a decade later with Riku Sanjō’s Zyuden Sentai Kyoryuger, and would not be repeated in Kamen Rider until Yuya Takahashi did it in Kamen Rider Ex-Aid.
Creator Backlash: According to a radio interview hosted by Hiroshi Kamiya and Kenichi Suzumura, Kohei Murakami admitted that Kusaka's death under Kiba's hands was made under a trick question by Toshiki Inoue when being asked over which character that Kusaka should not be killed by. Murakami still voiced his regret to this day for being too honest, wishing that he would prefer to be killed by Takumi and/or going down in a valiant fight against Hanagata and Kitazaki.
In complete contrast to their characters' relationship on the show itself, Takumi and Kusaka's actors Kento Handa and Kohei Murakami are very good friends in real life and continue to be even years after the series ended. It's very amusing to see the contrast between their characters on the show and their actors making a 555-themed shitpost parody to promote Murakami's crayfish song.
Murakami and Toshiki Inoue famously share a close relationship that came about from working on 555, to the point that they themselves have frequently teased it as being a borderline Romance on the Set. Inoue frequently tries to bring Murakami on board his projects if possible (such as his role as Sonoya in Avataro Sentai Donbrothers), and reportedly gets sad if he cannot (he wanted to have Murakami cameo in some way for 555's collab event with Symphogear XDU, but due to contract reasons regarding actor likeness, he could not. He was quite depressed about it).
Irony as She Is Cast: Satoshi Matsuda voicing the Crab Orphnoch is this. Given that he the previous series has his character fight a crab-themed Rider and his monster, the actor reveals that he is also allergic to crabs.
Meme Acknowledgement: Due to how famous it is to "celebrate" Masato Kusaka on September 13 (9/13), on that very date on 2019, the retelling of Kaixa Gear arc Kamen Rider 913 was first announced on that date.
Real Life Writes the Plot: Takumi's infamous absence from much of the first episode was because of the actor still being in high-school at the time of filming, and thus being unable to make it to where the first episode was being shot.
What Could Have Been: There are few elements that never made it to final production.
Early on it was pitched for Takumi to be the Grasshopper Orphnoch till it was changed to a wolf, with the grasshopper motif was retrofitted later on as the Arch Orphnoch.
hosted by Hiroshi Kamiya and Kenichi Suzumura, Kohei Murakami admitted that Kusaka's death under Kiba's hands was made under a trick question by Toshiki Inoue when being asked over which character that Kusaka should not be killed by. Murakami still voiced his regret to this day for being too honest, wishing that he would prefer to be killed by Takumi and/or going down in a valiant fight against Hanagata and Kitazaki.
