Two OVA episodes are bundled as DVDs with each of volumes 6 and 7 of the manga. The first OVA is a prequel story written by the manga's author. Before the beginning of the main story, Rea and Chihiro have already met at a certain place: an outdoor hot-spring bath. The second OVA takes place after the series (effectively episode 14). The Furuya family finds a mysterious young girl hiding under the household temple.

All is well at the Tendo residence when from out of nowhere, a Chinese girl named Lychee appears, seeking revenge on Happosai for a broken promise made since her birth. Things get worse when Kirin and the Seven Lucky Gods appear and abduct Akane to take as his wife. Ranma and the gang must travel to Nekonron, China, and save Akane from getting married to Kirin.

The beautiful Alamos Town is home to a pair of century-old structures known as the Space-Time Towers, built by the architect Godey to play orchestral music in the area. The towers are also home to the Alamos Town Contest Hall, which is the next destination for Hikari, Satoshi, and Takeshi in their journey through the Sinnoh region. A woman named Alice and her partner Chimchar are happy to guide Satoshi and his friends through the town and its hallmarks.

But the tour is suddenly interrupted when Alice's friend Tonio notices a wave of dimensional disturbances throughout the town—all of which is blamed on an ominous Pokémon named Darkrai. The space-time disturbances continue to intensify as two legendary Pokémon, the Temporal Pokémon Dialga and the Spatial Pokémon Palkia, appear to duel each other, isolating the town and everyone present in it from the world into another dimension!

As he learns that this event was foreseen long ago, Tonio finds that his great-grandfather left behind a way to stop the dueling Pokémon. Will Satoshi and his friends be able to use this last resort to save Alamos Town from vaporizing between the dimensions?

[Written by MAL Rewrite]

Iroe Genma is a third-year high school student often referred to as "Elder Sister" despite her short height. This troublemaking teenager is the president of her school's Model Club, which is dedicated to building plastic models of various objects and structures, such as cars, boats, and even robots. Joined by her two underclassmen, the violent Hazuki "Okappa" Okamoto and the rational Makina "Makimaki" Sakamaki, the small group aims to carry out their club duties but are often sidetracked by a myriad of distractions. From battles between club members to lessons on how to confess to your crush, these three schoolgirls get caught up in all sorts of wacky, and downright outrageous situations!