竜頭蛇尾

1. Origins, structure, and basic meaning

• Structure: 竜頭蛇尾(りゅうとうだび) is a noun for something that starts strongly but finishes weakly or anticlimactically.
• Basic usage: Such an outcome appears in 竜頭蛇尾に終わる, while avoiding that shape in a story appears in 物語を竜頭蛇尾にしない.

2. Common pitfalls and similar expressions

• Contrast between start and finish
  • It does not merely mean a bad result; the key is the contrast between an impressive beginning and a weak ending.
• State and change
  • Use 竜頭蛇尾に終わる for ending that way and 竜頭蛇尾にする for making something take that form.