GATE: Jieitai Kanochi nite, Kaku Tatakaeri
The military fantasy series begins when a gate appears in Tokyo's Ginza district sometime in the 21st century. From the gate pours out monsters, knights from middle-age Europe, and other fantasy-like beings, and they kill many of the citizens of Tokyo. This event is known as the Ginza Incident.
The government sends a small group of soldiers from the Japanese Self-Defense Forces (a replacement for Japan's military) to the alternate world beyond the gate. Led by otaku soldier Youji, they find that the villages in the world are being attacked by a dragon. An elf girl who is a survivor from the dragon's rampage joins the group in their travels across the dangerous new world.
(Source: Anime News Network)
Episode 1 - The Self-Defense Force Goes to Another World
Episode 2 - The Two Armies
Episode 3 - Fire Dragon
Episode 4 - To Unknown Lands
Episode 5 - The Battle of Italica
Episode 6 - Ride of the Valkyries
Episode 7 - The Princess's Decision
Episode 8 - Japan, Beyond the Gate
Episode 9 - The Hakone Mountain Night Battle
Episode 10 - Despair and Hope
Episode 11 - Visitor
Episode 12 - What Would Itami Do?
Episode 13 - The Banquet Begins
Episode 14 - The Imperial Capital Quake
Episode 15 - Tuka Luna Marceau
Episode 16 - The Fire Dragon, Once More
Episode 17 - Decisive Battle
Episode 18 - The Magic City of Rondel
Episode 19 - Dangerous Sisters
Episode 20 - Lover
Episode 21 - Deadline
Episode 22 - The Empress in Slave's Clothing
Episode 23 - Paradrop
Episode 24 - Thus They Fought