Tsukubai is a wash basin usually situated in front of the entrance of buildings or premises considered sacred. Washing hands and rinsing mouth are thought to be the way to purify ourselves. This Tsukubai situated in the northeastern garden of Ryoanji is not an original one but its motif on the surface is unique. The center square is a part of Kanji, Chinese character, and other four arranged on the top, right, bottom and left are also parts of Kanji. Incorporating the square and another part together makes one Kanji. Some concept of Zen Buddhism appears by arranging four kanjis. Taking a look at photos above, simply can be read “I just sufficiency know”. In other words, it means that I am content with what I am(have). Zen Buddhism is seeking nothingness and human is considered imperfect. Therefore, we can only see 14 rocks on the Ryouanji’s Rock Garden from any point though there are actually 15 rocks. It is said that you might be able to see all of them if you could achieve enlightenment.