Bei Mondaufgang werden die Spielerstädte Akiba, Susukino und Minami gleichzeitig von Schwärmen von Ewigkeitsmotten angegriffen, die Flügelstaub herabregnen lassen. Dadurch versetzen sie die Menschen in einen Schlafzustand, bei dem sie stetig ihre MP verlieren.
At moonrise, the player cities of Akihabara, Susukino and Minami are all simultaneously attacked by swarms of Eternal Moth monsters, whose scales rain down and knock people into a state of sleep by draining their magic points. The Brigade of the West Wind soon discover the moths' nest located in a new raid zone in the Shibuya broadcast building and the Round Table postulate that the monsters had been drawn to the broadcasting antenna from the Moon. Filled with uncertainty, Shiroe decides to put together a raiding party and makes the difficult choice of destroying the antenna. The raiding party then fights their way through Shibuya and manage to enter the raid zone in the broadcast building. However Shiroe's uncertainty hinders his strategic insight and allows the sheer volume of monsters to overwhelm the party from all angles, forcing them to make a hasty retreat.
Alors que les papillons de nuit éternels donnent à tous du fil à retordre, Shiroe fait face à un dilemme en se rendant à Shibuya.
月の出とともにヤマト各地を襲う、未知なるモンスター・常蛾(じょうが)。大地人のみならず冒険者までもが、次々とMPを奪われ眠りに落ちてゆく…。シロエは、常蛾の拠点であるシブヤの放送局跡「呼び声の砦(とりで)」攻略に踏み切るが、もしモンスターもろともアンテナを破壊してしまえば、月との通信手段が断たれてしまう。ジレンマを抱えたシロエのレイド指揮には迷いが生じ、戦線は大混乱におちいるのだった。
아키바를 습격한 나방을 처치하기 위해 시부야로 가는 시로에 일행. 하지만 평소와 같지 않은 시로에의 모습에 모두들 당황한다. 안테나와 대지인들의 안전을 두고 시로에는 갈등하는데…
La aparición de las extrañas polillas que duermen a la Gente del Pueblo solo consigue añadir un nuevo problema a las preocupaciones de Shiroe y los demás. Por otro lado, deberán encarar un raid que será vital en la posible vuelta a casa.
O ataques das mariposas preocupa Shiroe, ainda mais quando reportam a posição do ninho delas. Alguém está os impedindo de entrar em contato com a Lua. Mas quem?