Shokei sareta Shinimodori no Dairoku Ouji wa Kokoku wo Sute, Ringoku no Guillotine Koujo to Fukushuu wo Chikau

"Rejoice, Gustav! You're engaged to Princess Abigail, the first princess of the Strasclaid Empire!"

Gustav heard these words from his father, the king, for the second time. Gustav, the sixth prince of the Valrois Kingdom, was actually living his second life. In his first life, he had been betrayed by the kingdom, the king, his five brothers, and the one person he had believed in as his ally, the saint Cecile. He had been executed on the guillotine. However, in this second life, he would survive. He would seek revenge on all those who had betrayed him, and he would bring despair and suffering to them. And then...

"Gustav, I've always... loved you."

He would learn the continuation of the last words of his fiancee in his first life, the "Guillotine Princess" Abigail. This is the story of a man betrayed by everyone, who, in a world where he returns from death, finds happiness alongside a princess who doesn't smile.