Tomoki has another dream where the mysterious angel warns him of another Angeloid and after revealing the information to his friends, Nymph suggests they visit his dream via Dive Game which enables them to visit humans' dreams. The group, consisting of Tomoki, Sugata, Mikako and Suhara, leave into the dream to find themselves confronted with each other's dreams and an embarrassing revelation for Suhara. Ultimately, they are unable to visit Tomoki's dream and instead land on a bizarre world with a pillar with illegible words and hibernating evergreen trees. They return with more questions than answers and Sugata finally remembers a forgotten memory a year past when Ikaros first fell onto the Earth and winesses Astraea's arrival.

Tomoki, much to his irritation and confusion, finds himself aroused by the antics of Ikaros and Nymph. This disturbs him greatly so he leaves for the mountains to train in the Zen monastery. At the same time, Astraea, the new angeloid lands at the monastery to dispatch Tomoki while Sugata informs the rest about her. Nymph and Ikaros ignore the threat calling Astaea an 'idiot' and leave Tomoki alone who himself is finding trouble ridding himself of his 'earthly desires'. Later, Sugata discovers Astraea and learns of the threat to Tomoki's life and more information on Synapse, the world where Angeloids come from.

After unexpectedly divulging information of her assignment, Astraea attempts to attack Sugata to keep her secret safe. Unfortunately, she falls into the hands of Mikako, who upon seeing the gullible nature of the new Angeloid, fools her into joining a wrestling match at the local festival. Much like last time, Mikako entices Tomoki to join by putting up a prize of ten million yen and a chance to bathe with her family's geisha. Nymph wrestles with her emotions after losing her wings and master and finds herself yearning for a new one, Tomoki being her new candidate.

Winter comes to the city and Astraea is still far from completing her mission of eliminating Tomoki. Mikako reels her into another of her sadistic tantrums and stages a mock battle between the girls and boys of her school by appointing Tomoki as the general of the boys' group while acting as the general of the girls' group herself. This time, she entices Tomoki to fall into her trap by putting up the reward to be able to do anything to the losing team. Nymph still yearns for a new master and Astraea faces a dilemma when she is unable to dispatch Tomoki due to his question to her actions being her own choice or not.

Sugata and Sohara travel to Synapse with the aid of Nymph. Sohara accidentally drops an object onto the world below which falls into the hands of Tomoki who fashions it into a pedal bike that transforms into a robot. At Synapse, the two humans learn new details about the New World while Tomoki relishes his time with his new toy to satisfy his perverse actions. Sohara later destroys the toy and a new Angeloid is revealed post credits.

Astraea gets enrolled at Tomoki's school and tries unsuccessfully to dispatch of him. Later on, Nymph, Mikako, Sohara, Tomoki and Astraea join in a quiz competition to determine that Tomoki himself is not an 'idiot' as labeled by his schoolmates. His attempt proves futile and the events leave him to be an 'idiot' to the whole city than just in the school before. Astraea finds herself spending time with the group and acceptance which adds onto her dilemma and Daedalus discovers that Chaos, the new second generation Angeloid has been sent to Earth.

Even though they know it's a risky move, Astraea and Nymph decide to raid Ikaros's watermelon patch. Meanwhile, Sugata and Nymph find themselves in serious danger after infiltrating Synapse.

The time has arrived for Astraea to make a choice. Will she do the Sky Master's bidding and destroy Ikaros and Nymph once and for all? Or will she listen to Tomoki and find the strength to choose her own destiny?

During the Summer Festival, Mikako organizes a fishing contest at the swimming pool. There's only one way to win: reel in the curviest catch! Later, Ikaros tries to find the best way to spend her allowance.

Sohara teaches Ikaros about the ins and outs of marriage. Meanwhile, Tomoki puts the final touches on his summer project: a massive network of periscope-like tubing that allows him to sneak a peek at girls all over town!

Tomoki takes action when Ikaros, Nymph, and Astraea are overpowered in battle against Chaos! After the fight ends, it looks like peaceful days are ahead - until it becomes obvious that Ikaros still faces a serious crisis.

Tomoki makes a splash with the girls in swim class when he transforms into pool water. Later, the whole gang heads to a wedding - but who will be walking down the aisle?