レクイエム means “requiem,” a solemn piece of music or prayer for the dead. In the song, a faint requiem flows from a southern island, deepening the themes of loss, remembrance, and peace for the child who will not return. It is a memorable loanword with a powerful connection to the song’s mournful atmosphere.
This is a Janne Da Arc song that keeps its voice low and lets the grief do the talking. It opens with a wish: "そっと 風にのって" [gently, riding the wind], the singer wants to send "白い花と 祈りを" [white flowers and a prayer] somewhere far away. Then the picture gets dark fast. There is "暗い海を漂う 少年" [a boy drifting on a dark sea], and the waves sing a lullaby that puts the whole town to sleep. That lullaby is not a comforting one. It is the sea swallowing everything: "夢も想い出も" [dreams and memories] and "願いさえも‥呑み込まれ" [even wishes, swallowed up].
The middle of the song is the hardest part. Even if children's smiles come back to this town one day, "あの子はもう還らない" [that child will never come back]. The verb 還る is a nice one to learn here: it means to return, often with a sense of going back home, and the song uses it again at the end when it asks for wind strong enough that the child's soul can rise and "空へ還れる様に" [return to the sky]. The parents get one blunt line each. The father waits for night so he can be alone and cry quietly, and the mother runs "海へ" [to the sea] chasing her child. The singer also promises "12月の空 忘れはしないから" [I will never forget that December sky], so the loss is tied to one specific month. It ends small, almost whispered: "届きます様に" [may it reach you], a set phrase for sending a hope or prayer to someone. Learn that one, you will hear it everywhere.