“A Cruel Angel's Thesis” (残酷な天使のテーゼ, zankoku na tenshi no tēze) opens the 1995 anime Neon Genesis Evangelion, the story of teenagers who pilot giant machines against mysterious “Angels”. Yoko Takahashi sings to a boy at a window, full of potential he doesn't see yet: one day he'll spread his wings and become a legend.
Decades later it's still one of the most-sung songs at Japanese karaoke, and its opening line is famous even among people who've never seen the show.
The lyrics are dramatic and poetic, but the key words are concrete: cruel, angel, boy, myth, window, wings. Learn them and the song's grand mood will make sense.