Shinya Kougami continues to wander the Southeast Asian Union (SEAUn) away from the eyes of the Sibyl System in Japan. While travelling through the Tibet-Himalayan Alliance Kingdom, Kougami encounters Guillermo Garcia—commander of a paramilitary group attempting to unite the local factions and bring peace to the war-torn nation. Wary of joining another mercenary group, Kougami declines to join his cause, but agrees to be driven to the nearby Tibetan capital by one of Garcia’s men. However, Kougami's plan to remain uninvolved is short-lived when a bus of refugees are ambushed by armed guerrillas. Among them is a half-Japanese, half-Tibetan girl named Tenzing Wangchuck. Impressed with Kougami's fighting prowess as he single-handedly takes the attackers out, Wangchuck requests him to teach her how to fight so she can take revenge against the warlord who murdered her family. Knowing first-hand that there's no turning back to the person you were once you take a human life, Kougami is initially reluctant to accept her request. But faced with the girl's desire for vengeance that mirrors the haunting abyss inside his own heart, will he train her?

Due to the incredible success of the Sibyl System, Japan has begun exporting the technology to other countries with the hope that it will one day be used all around the world. In order to test its effectiveness in a foreign location, the war-torn state of the South East Asian Union (SEAUn) decides to implement the system, hoping to bring peace and stability to the town of Shambala Float and keep the population in check.

However, a group of anti-Sibyl terrorists arrive in Japan, and the Ministry of Welfare's Public Safety Bureau discovers significant evidence that the invaders are being aided by Shinya Kougami, a former Enforcer who went rogue. Because of their past relationship, Akane Tsunemori is sent to SEAUn to bring him back, but with their last meeting years in the past, their reunion might not go quite as planned.

Ikta Solork is a carefree young man who only wants two things in life: a woman on his arm and a place to nap. Unfortunately, his peaceful life is destroyed when war breaks out between the Katjvarna Empire and the neighboring Republic of Kioka. Ikta and his childhood friend, Yatorishino Igsem, join the army as military officers, where they meet the infantryman Matthew Tetojirichi, the sniper Torway Remion, and the medic Haroma Becker on a boat heading for the military exam site. However, after a rogue storm sinks their vessel, the five of them end up in enemy territory near a military outpost. There, they discover that the heir to the Katjvarnan throne, Princess Chamille Kitora Katjvanmaninik, has been taken hostage. The five are able to rescue her, and as a reward, each one of them is granted the title of Imperial Knight—one of the highest honors a soldier can receive. It seems that Ikta will have to put his dream of tranquility on hold, as he must now become the hero he never wanted to be. [Written by MAL Rewrite]

The main additions in "Little Busters! Ecstasy" are 3 heroine routes involving the characters Futaki Kanata, Sasasegawa Sasami and Tokido Saya. The 3 EX heroines' routes take place of the following: Saya's route - Before the events of Refrain. Sasami's route - After the events of Refrain. Kanata's route - First half of her story is before Refrain and second half is after Refrain. The episodes will be bundled with the BD/DVD releases of Little Busters!: Refrain.