WARNING: The following contains spoilers for Platinum End Episode 18, "Last Supper," now streaming on Crunchyroll and Funimation.
Ever since the climactic death of Metropoliman, the surviving God candidates have been fighting a battle of wits rather than one of arrows and bullets to conclude the divine battle royale to decide the next God. The youthful Yuito Susumu went on TV to propose an election among the candidates, but it won't be that easy.
The union of God candidates now includes the depressed and troubled Nakaumi Shuji, and the five God candidates recognize both Kakehashi Mirai and Shuji as the two best candidates to become God. The problem is, the two boys have differing views on how God should handle people who wish to end their own lives. This reveals something about each of them.
In previous episodes, Yuito Susumu expressed his preference for Mirai/Red becoming the next God, especially given Mirai's balanced view on the world and his role in defeating Metropoliman. Yuito, Mirai and Saki teamed up to recruit Shuji next, and in Episode 18, they take a risk by recruiting Temari Yuri, who has thus far not taken part in the battle royale.
So far, the plan is working, but then the reality of actually becoming God sinks in. It's easy for anyone to say "I wish I were God" and describe their ideal world, but Mirai and Shuji know that certain sacrifices are involved. Whoever becomes God must give up their life on Earth as an ordinary human being and spend centuries in Heaven, and the hedonistic Yuri doesn't want to make that sacrifice. Police officer Yumiki, under the red arrow's control, doesn't want her ally Hanakago Saki to leave Earth, either. Meanwhile, Susumu doesn't want to become God at all.
This narrows it down to Mirai and Shuji, and the two boys are both willing to become God but have differing ideas on what justice and compassion for humanity look like. Shuji, who already desires to end his own life, declares that as God, he would create a world where such things are tolerated and there is no stigma against taking one's own life. Mirai objects to that, stating that gaining the arrows and wings gave him hope to survive and create a future of happiness and peace.
Shuji sees red arrows and Godhood itself as enablers for people taking their own lives, and he considers it mercy. Mirai feels differently, and that costs him votes among the God candidates. Mirai's idealistic, shonen-style attitude is a firm one, and that means he and Shuji are now in direct competition for Godhood and Earth's future.
Mirai loses favor with the other God candidates for several reasons, mainly because as God, he wouldn't allow any humans to use the heavenly wings or arrows, while Shuji says he would allow any God candidate who wants to keep their arrows to do so, such as Yuri. Shuji's mindset is disturbing but flexible, while Mirai insists on a more rigid and hopeful vision of his own Godhood.
As a shonen protagonist, Mirai doesn't just want to win -- he wants to win on his terms and seek an optimal outcome for everyone. He won't just give up hope, nor will he allow anyone else to do so. Allowing other people to take their own lives is unacceptable to him, viewing it as a personal failure to fight for happiness in life. Death is defeat in Mirai's eyes, including when people take their own lives on purpose, so he opposes it. Mirai wants everyone to go on a quest to find hope and happiness, like him, so he rejects Shuji's vision of Godhood.
Despite Mirai's noble principles, he loses the popular vote, and the five God candidates decide by a majority to nominate Shuji as the next God. If the final God candidate agrees, the battle royale will end, and Shuji will become God and create a world where people are free to take their own lives when they wish to, and Yuri can keep her red arrow. Mirai can't accept that, but for now, there's little he can do except hope that the final God candidate's ideas may change everyone's mind and convince them to see things Mirai's way after all. He's running out of options.
