Yume de Aetara is a story about one guy Fuguno Masuo (a complete loser when it comes to relationship with women) and two girls: Shiozaki Nagisa and Hamaoka Miho. Since the story is pretty simple (and hilariously funny), further explanation will spoil everything (take the hint: watch it yourself!) (Source: AniDB)

Fuguno Matsuo has never had a girlfriend all his 24 years in life and what makes things worse is that a fortune teller predicted that he never will. However, when he laid his eye on Nagisa-sensei he fell in-love right away and began earnestly wooing her. Along comes Hamaoka, a co-worker who is smitten with Fuguno, and a love-triangle ensues.

High school student Yumeji Fujiwara has the ability to see people's dreams. Despite the visions never appearing clear or concrete, he is able to predict them by sensing the person's aura. Normally, this skill is a fun trick to play on his classmates, but Yumeji only ever sees himself having the same nightmare every night. To his surprise, the nightmare continues in the middle of the day even before Yumeji has fallen asleep. The unexpected event was triggered by a dream demon—an inhabitant of the world of dreams who wants to use Yumeji's body as a vessel to fully enter the real world. However, Yumeji is saved by the timely arrival of Merry Nightmare, another dream demon who can somehow physically manifest without a host and is instead trying to return to her own realm. As more dream demons continue to push into reality, it is up to Yumeji and Merry to fight back against the invasion before everyone's nightmares materialize.

Following his brave sacrifice in the war against Albion, Saito Hiraga is knighted and treated as an aristocrat, something that proves difficult for Louise Françoise Le Blanc de La Vallière. With their relationship no longer defined as the mighty Void mage and clueless familiar, she wonders what exactly this means for them. While venturing to a castle, Louise is ambushed by a powerful mage named Sheffield. Battling alone, the young mage nearly faces defeat until Saito makes his appearance. The mystical and unknown nature of Void magic seems to be at work in the battle, and Louise begins to believe in the possibility of another Void user. Moreover, she realizes that Saito's magical rune is fading, and so a new adventure begins as they search for the elf who revived Saito in the past. The relationship between former master and servant faces a new challenge as they work to restore the runes and redefine the bond which holds them together.