Volume 5

Volume 5 is the fifth volume of Mars. It was published on September 12, 1997 in Japan and October 22, 2002 worldwide. In this chapter, Rei gets sick, so Kira stays with him at his apartment. While there, Kira learns why Sei killed himself. Back at school, Shiori still loves Rei, despite him being with Kira.

Description
Kira and Rei's roller-coaster romance continues! When Rei suddenly gets ill, Kira takes care of him at his apartment...and ends up sleeping over. After their night together, Rei finally tells Kira the real reason his twin brother Sei killed himself: Rei told him a secret he knew Sei would never be able to handle. Kira tries to comfort Rei, but secretly wonders if mere words have the power to ease the pain Rei harbors deep inside. Meanwhile, Kira's best friend, Harumi, warns Kira if she doesn't start sleeping with Rei soon, he'll probably break up with her. Ouch! Kira's worries deepen when Rei's ex-girlfriend tells him she's still in love with him - and will do anything to win him back. With the pressure mounting by the minute, Kira is about to make the biggest decisions of her life!

Characters

 * Rei Kashino
 * Kira Aso
 * Tatsuya Kida
 * Harumi Sugihara
 * Shiori Sakurazawa
 * Takemura Shuichi
 * Sei Kashino (flashback)
 * Takayuki Kashino (debut)