- Note: This article is part of the Seihou Project by the Doujin circle "Shunsatsu sare do?".
The Holy Grail (聖杯 seihai) is part of Christianity that is a dish, plate, stone, or cup artifact that's said to have held the blood of Christ after his crucifixion.
The Grail hasn't been referenced in the Touhou Project, but it has in the Seihou Project. Erich for some reason wants the Grail, so in Shuusou Gyoku's extra stage, VIVIT was given an errand by Erich to go look for the Grail, but must find it within one day. She went to "the East" where she met Marisa Kirisame and Reimu Hakurei. It appears that Marisa has an idea what the Grail is, but Reimu was lost on what it was. VIVIT then appeared in the extra of Samidare and encountered C23 on the same day, thinking that she had the Grail. It is unknown if VIVIT managed to find the grail within this one day.