Nightmare! Incense of Spring Sleep (悪夢! 春眠香 Akumu! Shunminkō?) is the most recent OVA to be released. It debuted in 2008, after a twelve-year gap. It was created to celebrate the 50th anniversary of Shōnen Sunday and as such was released with a special non-cannon mini-episode which featured characters from two of Rumiko Takahashi's other notable works, Urusei Yatsura and InuYasha. Its style differed from previous anime in the series, as it was released in high definition, and was animated using digital ink and paint animation instead of cel animation.