This short OVA series is an adaptation of some manga arc which decided not to fit into the main story line, which honestly makes sense, not only is it a self-contained story, in terms of quality it feels more like the late season 1 rather than season 3 (4?) material. The arc has virtually no value as a story, and it can be easily skipped, take it from someone who despises skippers in pretty much any anime. The antagonist was introduced in this arc and will most likely never be seen again. And even unlike other "useless" arcs such as the Renho arc, it doesn't evenbring the little but still somewhat useful addition to the greater narrative.

This arc's main draw is definitely in its events unfolding. I don't think I'm spoiling anything if I say the Love Incense arc is about... an incense which make people fall in love. Not only does this create some very entertaining situtions but it's also fairly unique (as far as unique goes in Gintama) because it breaks apart the relationships that grew over the episodes. The rest is fairly Gintama so if you're into that, enjoy.