The Ideal Sponger Life: Volume 4 (Light Novel) by Tsunehiko Watanabe

Prince Francesco and Princess Bona of the Sharou family have finally arrived in Capua, marking the end of a century or so of the royal family’s isolation within the Twin Kingdoms. While the prince is all too likely to be seen laughing uproariously as he causes trouble, his sister bows her head diffidently, timid yet serious.

Zenjirou spends his days entertaining the prince until he receives ill-tidings: his beloved son has fallen ill. The disease has a relatively low mortality rate, but a lower-risk illness means that a healing gem won’t be permitted—a fact that deeply frustrates the new prince consort.

Francesco makes an offer that Zenjirou, witnessing his son suffering as he is, can’t help but accept. The prince offers to use a healing gem of his own on the child. Yet when they stand at his bedside to perform the ritual, Zenjirou realizes that the gem isn’t what’s being used to treat little Carlos...