No dream is too big for Appare Sorrano, a socially-awkward inventor living in a small rural town in Japan in the late 19th century. Fascinated since childhood by the creation of steamships that can connect people across great distances, he's learned to make machines of all kinds from various scientific texts. His goal is to sail across the sea, beyond the sky, and ultimately, to the other side of the moon. Unfortunately, through a string of events, Appare finds himself stranded in the middle of the sea on his mini steamship. Floating alongside him is a skilled but cowardly samurai, Kosame Ishikki, who was tasked to keep his eccentric behavior in check. Just when all hope seems lost, a large steamship saves them and takes them to Los Angeles. With no money or plans, they decide to participate in the "Trans-America Wild Race," which gives Appare the chance to build his own automobile, and Kosame the opportunity to use the cash prize to return home. However, against rival racers and unknown challenges residing in the wilderness, just how far will this adventure take Appare and Kosame?

In their teenage years, few things can hurt people more than the heartaches that come with unrequited love. Such is the case for Natsuo Fujii, who has found himself entranced by his school's ever-cheerful teacher Hina. Deflated by this unreachable desire, Natsuo humors his friends and attends a mixer. There he meets Rui, a girl whose lack of excitement rivals that of himself. After bonding over their mutual awkwardness, Rui takes Natsuo to her house and asks him to have sex with her, hoping that the experience will stop her friends from treating her like a clueless child. With his hopeless feelings towards Hina still on his mind, Natsuo hesitantly agrees. Equally unfulfilled by their "first times," the two decide to part ways as strangers. However, before he even has a chance to process this experience, Natsuo's father drops a major bombshell: he is getting remarried, and his new wife Tsukiko Tachibana is coming over now to meet Natsuo. As if that was not enough of a shock, her daughters—and, in turn, Natsuo's new sisters—are Hina and Rui Tachibana, the woman he's in love with and the girl with whom he shared his first night. Now, Natsuo must come to terms with the feelings he has for his step-siblings as his eyes open to a darker side of love.

Satou Matsuzaka is a beautiful high schooler who has a reputation for being permissive with men. However, a chance encounter with a young girl named Shio Koube makes Satou realize that this is her first and only true feeling of love. Telling others that she lives with her aunt, Satou secretly shares an apartment with Shio. Despite her innocent appearance, Satou is willing to do anything to protect her beloved, resorting to desperate measures to ensure that their "happy sugar life" remains intact.

Novice bounty hunter Chateau Dankworth never expected to encounter someone capable of overpowering her in combat. Even less so that the mysterious man would take an immediate interest in her—to the point of aiding her missions. However, Chateau makes it clear that she has no plans of entertaining any personal involvement with him. Chateau's company is soon tasked with eliminating Song Ryang-ha—an expert assassin and a former member of a powerful Asian organization. Coincidentally, Ryang-ha is the man that has been pursuing her. Despite his background, Chateau reluctantly agrees to meet with Ryang-ha as part of a deal: in exchange for going out with him, he will provide her with the locations of current targets, dead or alive. But when the past begins to haunt both killers, their arrangement may need to come to an end, as their entanglement puts their lives at grave risk.