不朽少女失他失命不朽少年失她失心
[bù xiŭ shăo nǚ shī tā shī mìng bù xiŭ shăo nián shī tā shī xīn]
Translating directly would be quite convoluted: an immortal girl who loses her life over someone and an immortal boy who loses his heart over someone. It's probably expressing a complex emotion of lost love, eternal longing, perhaps influenced by some dramatic narrative seen in literature, games, or anime.