Therapy Planet No. 13, also known as 13号治疗星球 or sanshi hao zhiliao xingqiu, is a captivating web novel in Chinese that follows a Federation Colonel who, plagued by morbid thoughts, finds himself confined in a dark room where he encounters an eccentric individual. The story unfolds as the Colonel's icy demeanor clashes with the whimsical nature of his new roommate, leading to an unexpected journey through the depths of outer space. With themes of mecha, sci-fi, and yuri, this novel offers a unique blend of futuristic settings and interpersonal dynamics, making it a must-read for fans of the genre.