Ruru

Ruru is a Level 1 NPC of the 56th Floor. She accompanies the heroes through much of the ordeal to clear the Geocrawler boss, and generally shows concern for most of the players.

Ruru's Lullaby
After Asuna is defeated in a duel with Kirito, Ruru sings a lullaby to Asuna:

"The southern travelling musician

With a lute in his hand

With a brush of silver threads

La, La-la, sleep awaits

Village chief with his long beard

Weapon shop uncle of greed

Kid's running through the plaza

A black cat up the roof

A robin singing atop a twig

Even the serpent, armored in iron

Da, da-da, da, da-da

Everyone's asleep." It turns out that Ruru's lullaby is the secret to defeating the Geocrawler. By singing Ruru's Lullaby, the Geocrawler instantly falls asleep allowing the players to defeat it.