The fate of Megumi's softball club at hangs in the balance as she plays with a hodgepodge team against NIT's baseball club in a match to determine which team will absorb the other.
Summary
At Nekomi Tech, Keiichi once again compliments Belldandy's cooking, but Megumi runs up to them and says that there's big trouble. She brings them to the school's baseball diamond where the baseball club is practicing. As Megumi explains, today is supposed to be reserved for her softball club, but the baseball club kicked them off because they're short on players. Keiichi tells her she could always join the motor club, but Megumi insists that she wants to keep playing softball.
The leader of the baseball club, named Yamagata by his jersey, meets them and taunts Megumi by offering to let her join his club as a gofer (someone who fetches things for other people). As for breaking the "promise" that he had with the softball club, Yamagata says that four players don't make a softball team, and that promise was never written down. Belldandy tells the man that promises carry weight regardless if they're recorded or not, and this nearly convinces him before deciding that they could decide the issue by having his team against the four of them.
Urd then suddenly appears and encourages Megumi to go all-in with the stakes, and suggests that the winner of the game could absorb the other team. Megumi goes along and requests that the game be played with softball rules and that her team can draft outsider players. Yamagata agrees to the terms and is elated at the thought of having Belldandy on his team.
At home, Skuld is mad that Urd roped Belldandy into Megumi's wager while she builds a special baseball bat, and Urd makes Keiichi do "special training" before their match because she saw it done in old sports anime.
The next day, Megumi shows up with a team consisting of herself, Keiichi, Belldandy, Urd, Skuld, Sora Hasegawa—whom Keiichi convinced to play with them—and Junko, a fellow softball club member, but they're missing the two other girls on the softball club. Thankfully Tamiya and Otaki have shown up disguised as the "Dynamite Baseball Brothers" and want to play too, although it turns out that they're the reason that the other girls are too scared to play.
The game begins and Belldandy is the first to bat while Yamagata is the pitcher. He communicates to his catcher that he wants to throw an inside pitch to scare the willies out of Belldandy, despite the risk associated with possibly hitting her. He throws the ball, but Belldandy doesn't even flinch as it passes by. His repeated attempts result in four balls and let Belldandy walk to first base. Next up to bat is Skuld, who is mad that Yamagata tried to hit her big sister. Using her specially made bat with an auto-tracking feature, Skuld sends the ball flying and lets Belldandy get to third base, but she herself gets out after she gets distracted by Yamagata calling her a kid.
While Megumi is bewildered that both Tamiya and Otaki have already struck out, Urd takes up the pitcher's mound and throws her intimidating "thunderbolt" pitch which seems so fast that the other team didn't even see it. However, it's ruled as an illegal pitch because it turns out Urd didn't actually let go of the ball. Megumi performs better, but the baseball team discovers a weakness in Sora playing on second base, as she is too timid to catch any balls. They launch a full-scale assault on her, and though Skuld tries to offset this with her auto-tracking glove, the baseball team builds a large lead going into the fourth inning.
Noticing that her team's spirits are down, Belldandy makes a cheesy pun and gets everyone laughing. She says that while it's important to be serious about what one does, one must also have fun doing it, or else it'll eventually become a burden. Her words inspire the team as the game continues, and Urd tries a new tactic as she goes up to bat. By unbuttoning the top of her uniform and distracting the baseball team with her chest, she turns them into a lot of blithering idiots and helps them overtake the baseball team.
Eventually, Yamagata comes to his senses and gets his batter to do the same, and the baseball team makes a comeback by hitting the ball between the first and second bases, where Skuld can't cover for Sora. The bottom of the ninth inning comes with the baseball team loaded on the bases, and the game hinges on whether Megumi's team can stop one last run. Megumi pitches, but Yamagata hits the ball that Sora is unable to catch, and Megumi remembers a time when she was in a similar position, having held back the rest of her team during a softball game and apologizing to Keiichi. However, Keiichi told her that it's more important to have fun playing than to win, and Megumi repeats the same to Sora when she apologizes to her for losing the game.
However, it turns out that the first baserunner on the baseball team failed to touch the home base, and once Keiichi tags him, that means their runs are disqualified and the softball team inadvertently wins the game! While Yamagata calls his baserunners idiots, Megumi decides against absorbing them into her softball team.