Kara-kun, Flip-kun

This two-part novel is set in Hiroshima, fifty years after the fact. The title character of Kara-Kun was in utero at the moment of the atom bomb's detonation, and is mentally deficient, like many such "bomb babies." His hobby is disrupting weddings at the cathedral. Not surprisingly, Kara-kun disappears soon after spoiling a Yakuza wedding...

In Flip-Kun, an American is being stalked through Hiroshima by "hit-missionaries" from a certain American pseudo-religion, whose patriarchs have declared a western-style fatwa on his head. "A wicked imagination...sheer invention..." (The Daily Yomiuri)