Kotonoha no Hana

After he suddenly began hearing the voices within people's hearts three years ago, Yomura has since become withdrawn and untrusting. One day, he inevitably hears the thoughts of Hasebe, a pure-hearted co-worker who has long harboured feelings for him. While feeling guilty at first about hearing Hasebe's inner-most thoughts, Yomura eventually grows fond of him, because Hasebe is very earnest with his love; the words he says and the "voice" in his heart are one and the same. But just when Yomura has heard Hasebe's confession and accepted his affections, Hasebe's reaction when he finds out that Yomura can hear people's thoughts is indeed unexpected. (Source: MangaUpdates)