夏の魔物 literally means “summer monster,” an imaginative phrase that makes summer feel like a mysterious force with the power to take someone away. In the song, the narrator wishes this “summer monster” would carry the girl to him, turning his intense, impossible crush into a playful summer fantasy.
"Takane no Hanako-san" is back number at their most painfully relatable. The singer is not even a friend of the girl he likes. He is "ただの友達の友達" (just a friend of a friend), and even the smile she gave him, a mere "知人B" (acquaintance B, like a background extra), was enough to wreck him. He calls her "恐ろしい人だ" (a scary person) for it, which is a very funny way to say she is dangerously charming. The title itself is a joke: "高嶺の花" is a Japanese idiom for a flower on a high peak, meaning someone out of your league, and turning it into "花子さん" gives her a name, like calling her Miss Out-Of-Reach.
The chorus is pure daydream. He begs her to "飛び出してきてくれないか" (won't you jump out and appear) from that corner right now, hoping a "夏の魔物" (summer monster) will carry her to him, and that chance plus "夏の魔法" (summer magic) will fix the fact that they were born under different stars. Then he deflates himself every time: "僕のものに なるわけないか" (there's no way you'd ever be mine, huh). The second verse is my favourite part. He builds her imaginary boyfriend in detail, older, tanned, into "洋楽" (Western music), with her standing on tiptoe to kiss him, and concludes "何ひとつ 勝ってない" (I don't beat him at a single thing) before snapping "そいつ誰だ" (who even is that guy). He invented the rival and lost to him anyway. By the end he is shivering under the midsummer sky, guessing "好きなアイスの味" (her favourite ice cream flavour), which says everything about how little he actually knows her.
back number is a Japanese rock trio formed in Gunma Prefecture in 2004 by singer and guitarist Iyori Shimizu, with Kazuya Kojima on bass and Hisashi Kurihara on drums.
The band signed to Universal Sigma and made its major-label debut in April 2011 with the single "Hanabira".