Watch Sadisflix. Nijiiro Days follows the colorful lives and romantic relationships of four high school boys—Natsuki Hashiba, a dreamer with delusions of love; Tomoya Matsunaga, a narcissistic playboy who has multiple girlfriends; Keiichi Katakura, a kinky sadist who always carries a whip; and Tsuyoshi Naoe, an otaku who has a cosplaying girlfriend.