"Shisukon Ouji" is a supernatural romance anime that centers around the relationship between a human girl and a ghost prince. The protagonist, a high school girl named Hana, possesses the ability to see spirits, a gift that isolates her from her peers. One day, she encounters a ghostly prince named Shisukon, who has been wandering the human world for centuries. Shisukon is bound to the mortal realm due to unresolved emotions tied to his tragic past, and he seeks Hana's help to uncover the truth behind his death and find peace.

As the story progresses, Hana and Shisukon form a deep bond, navigating the challenges of their unique connection. Hana assists Shisukon in piecing together fragmented memories of his life, which reveal his noble lineage, the betrayal that led to his demise, and his lingering attachment to a lost love. Their investigation takes them through historical sites, spiritual realms, and encounters with other spirits, each contributing to the unraveling of Shisukon's past.

The narrative explores themes of love, loss, and redemption, as Hana and Shisukon confront their own vulnerabilities. Hana's ability to see spirits becomes both a blessing and a curse, as it draws her deeper into the supernatural world, putting her at risk from malevolent entities. Meanwhile, Shisukon struggles with his growing feelings for Hana, knowing their relationship is inherently transient due to his ghostly nature.

Supporting characters include Hana's best friend, who provides emotional grounding, and a rival spirit with a mysterious connection to Shisukon's past. The series balances moments of lighthearted humor with poignant reflections on mortality and the enduring power of love. By the conclusion, the story resolves Shisukon's lingering regrets, offering a bittersweet yet satisfying resolution to his and Hana's journey.