(Moto no mokuami; “The former Mokuami”)
Back to square one; ending up where you started. For something, or a situation, to revert to a previous (worse) state after temporarily improving. The ur-example is of a poor person who gets to live a relatively lavish lifestyle for a while before being returned to a hardscrabble life, but this idiom can apply to anything that gets worse again after getting better for a while, especially if the getting-better part required significant effort that in retrospect feels wasted.
This simple idiom comprises two nouns, joined by the associative particle の (no). The primary noun is proper noun 木阿弥 (Mokuami), which turns out to be a guy’s name. The associated noun is 元 (moto), “origin.”
Especially in an age of computerized auto-kanji it might be easy to forget that 木 can be pronounced moku and replace it with 黙 (also moku), “silent,” but this is an error. On the other hand, some variants may replace 元 with 旧 (“old,” “former”) without any change in pronunciation or meaning, or replace 阿弥 with 庵 (an), “hermitage,” or 椀 (wan), “bowl,” without any change in meaning.
This phrase supposedly comes to us from the Warring States period, when a feudal lord named 筒井順昭 (Junshou Tsutsui) passed away from sickness while his son was still a minor. To keep up appearances until his son reached the age of majority, the family looked for a body double and found a commoner named Mokuami. The latter was allowed to eat good food, dress in fine clothing, and generally live the life of the lord of a castle… until the son reached adulthood. At this point he was returned to his previous life as “the former Mokuami.”
(“Paatii no mae ni, sekkaku zenryoku wo tsukushite oosouji shita no ni, ima kono heya wo mitara, moto no Mokuami ni nattete dotto tsukareta.”)
[“I went and worked as hard as I could to clean everything before the party. But looking at the room now, it’s right back where it started, and all of a sudden I’m tired.”]