The kanji 良 primarily conveys the idea of "good," "excellent," "virtuous," or "fine." It implies a positive quality, often related to something being of high quality, morally upright, or beneficial. It signifies goodness in various forms, from physical excellence to moral integrity.

・On-yomi (音読み): リョウ (ryou) ・Kun-yomi (訓読み): よ（い） (yo(i)) - good; よ（し） (yo(shi)) - good, alright

⚫︎ 良好（りょうこう） Translation: good; favorable; satisfactory ⚫︎ 善良（ぜんりょう） Translation: goodness; virtuousness; integrity ⚫︎ 品質（ひんしつ）が 良い Translation: The quality is good.

Unfortunately, I lack the information to provide a specific correspondence to Vietnamese, including Sino-Vietnamese words sharing the same origin as the kanji 良.

The kanji 良 is a pictograph. The original form depicted a building. Over time, it developed the meaning of "good" or "excellent". The top part is a simplified representation of a building’s roof, and the lower part has been interpreted differently. Some sources suggest it could represent a person or a field, or it could be a combination of different components with the meaning that it became. It represents the idea of something being solid and of good quality. The kanji evolved into its current form through simplification and stylistic changes.