Tinder Lightheart, a compassionate colt nearing adulthood, operates an orphanage previously run by his parents, with help from his brother Warden and his sister Airy. Together, the Lightheart siblings raise young orphans and see them off to new homes, giving them a chance to experience what true love and a family feels like. One filly, Felicity Gardens, has been in the orphanage for far too long, and while Tinder's fears for her grow, an unseen entity looms ever closer that threatens to rip apart everything he has worked to achieve. A story of turmoil and misfortune, An Instance of Happiness follows Tinder Lightheart and his family as they learn what a true family is, and discover it through their hardships, complicated further by the meddling mischievousness of Felicity.