This series tells the story of 9 year-old Katri, a girl who lives on a farm in Finland with her grandparents. Katri's mother has been away in Germany for three years. The farm is not doing well, so to help support her family, she goes to work on a neighboring farm. Katri faces many struggles and challenges.

As Yoko has her assistant scour the seabed in search of something, Madoka, unable to pilot Midori properly again, returns to Kamogawa to see the New Year in. Upon returning home, Madoka receives New Year's letters from Lan and Muginami, updating her about what's going on in their lives, to which Madoka makes a prompt reply. As the months pass by and Madoka moves up a year in school, Lan and Muginami visit an intergalactic replica of Kamogawa on the tourist planet Polyhedron. Takes place between seasons 1 and 2. (Source: Wikipedia)

Robotic OrderMaids are popping up in every household, and 10-year-old Bondo Taira has found out that his two closest friends—Motsuo and Gachi Gorilla—have OrderMaids too. Motsuo, in particular, owns Meico, a beautiful robot that gives excellent massages and serves drinks with a smile. Jealous of his friend, Bondo convinces his mother to get him an OrderMaid, hoping for a similar experience. However, to Bondo's surprise, the maid that appears outside of his door is incredibly muscular and clumsy enough to destroy a house when completing simple chores. Going by the name Roboko, this new robot is the exact opposite of what Bondo wanted. But despite that, Bondo, together with his friends, learns that there is more to Roboko than they could ever expect.

A great war occurred in the 20th century between humans and monsters. Since that time, the monsters rule the world in fear but keep relatively hidden from public view. A boy named Bokka ponders the past and wonders what became of the Meros Warriors who defended the world so bravely against the demons. He soon meets Kurofune and learns of the power of the Meros and the I-bar machines they ride in battle. Warriors are the only ones who can see and hear the Melody of Oblivion, a phantom girl hidden away waiting to be rescued and be the savior of mankind. During a battle between Kurofune and a demon, Bokka discovers something only his wildest dreams could possibly imagine...he too can hear that melody. Throughout his journeys, Bokka meets many monsters and their agents, friends, and companions as he discovers the true extent of his new powers. He must continue to battle evil in the hope of releasing Boukyaku no Senritsu and free a world that has forgotten its once beautiful melody.