Sputnik Sweetheart by Haruki Murakami

A woman fifteen years older has captured Sumire's heart, but while Miu is wealthy and accomplished, Sumire strives to become a writer and dresses like a character in a Kerouac book. Sumire turns to her best friend K for deep conversations about life's mysteries: love and whether to confess her feelings to Miu. Meanwhile, K struggles with his own unrequited love for Sumire. But then, Miu calls from a Greek island, frantically reporting that Sumire has vanished without a trace... Murakami's latest work, COLORLESS TSUKURU TAZAKI AND HIS YEARS OF PILGRIMAGE, delves into the inner workings of death and its impact on main character Tsukuru Tazaki, after his closest friends suddenly cut ties with him forever.