In the distant future of 2403 AD, a student named Satoru receives a visit from a charming time traveler named Alisa. Together, they journey back to the 21st century, but a mishap propels them through various pivotal moments of religious and historical significance. The anime, 'Kyoufuku no Kagaku' (The Institute for Research in Human Happiness), delves into their unexpected time-traveling escapades with a blend of intrigue and adventure.