Lina and Gourry travel to a seaside town named Acassi, where octopus tentacle is a delicacy. However, the octopus meat carries a curse that dooms the eater to only speak Takogo (octopus language). Amelia, Zelgadiss, and Xelloss all show up, and the main four characters (Lina, Gourry, Ameria, Zelgadiss) get cursed. The octopi enlist the power of a mazoku to get rid of the humans once and for all. The white sorceress Ruma must learn the cure to the curse from her long-lost master in order to save the town. 

(Source: ANN)

Deep in the dark recesses of the UnderNet, Forte sleeps as he drifts aimlessly. In this cybernetic graveyard, a pulsating power re-awakens Forte, alerting him to a dangerous being shortly ahead. A haunting face appears amidst a massive bright purple blob, laughing directly at Forte. Cursing him, Forte finds himself powerless as the blob takes form, and captures him within its grasp! Nearing the time of sunset, a peaceful city and its people go about their everyday business. Curious bystanders on a sidewalk glimpse a shimmering purple light, which suddenly expands into tall pillar that reaches up to the sky. Screams erupt from the people as the pillar of light takes flight, absorbing everything in its destructive path. A tower clock dings the hour of 4 o'clock as the pillar desintigrates, leaving behind a trail of cybernetic residue and utter emptyness. 'The Program of Light and Dark'

Doraemon and friends run away from their home and travel back in time to the 70,000 years ago where nobody existed to build their ideal private paradise. After they fully relished the freedom in the era, Doraemon and friends bid farewell to their paradise and come back to the present day. However, a few days after they came back home, Doraemon and friends bump into a caveman called "Kukul" in the current era. They find out that the caveman Kukul was accidentally transported forward to the present, and that his tribe called Hikari tribe was attacked and abducted by Giga Zombie and Kurayami tribe after Doraemon and friends left the primitive age.

Doraemon and friends decide to go back to the primitive age to save Hikari tribe from the villain.

They dive into a grand adventure during their first and the furthest runaway.

(Source: Toho)

Fifth Digimon Adventure tri film.