The homeland of the Genesect exists no more. After three hundred million years, the snowy mountains where the Paleozoic Pokemon once lived are no longer habitable — but not all of the race are actually extinct. Several specimens are still alive and desperate to find a new place to call home. Led by a Shiny Genesect and accompanied by the Legendary Pokemon Mewtwo, the vagabond creatures arrive in New Tork City.

Perceiving the city skyline as similar to their initial habitat, the Genesect take over the city center, driving out other Pokemon and threatening the existence of the local populace. On top of that, the Genesect leader confronts Mewtwo in a cunning, fast-paced duel that is bound to destroy the entire city – and it’s up to Satoshi and his companions to save the city and reconcile the feuding Pokemon.

[Written by MAL Rewrite]

ONA Special episode #11.5.

First-grader Masaya is a crybaby despite his large stature, so he can't walk by himself on the dark path to school. The one who holds his hand is Akiyo, a tiny but capable second-grader. Masaya wants to be strong like Akiyo and admires her, but one day, something happens that leaves Akiyo in tears. To lift Akiyo's spirits, Masaya goes trekking to the distant Ipponsugi forest to find the spotted bellflowers that Akiyo loves.

Nurarihyon no Mago Recaps.