Fukurou Kogyoku Book order (chronological)

"Akuto, a normal game-loving high schooler, and his older sister Tsukasa are summoned one day to a strange otherworld called Chiyodaku. There, a laidback princess tasks them with becoming judges for her kingdom! Akuto must help his sister, who knows nothing about fantasy worlds and their logic, navigate eccentric courtroom characters as the siblings pursue the truth, no matter where it leads"--