Don't Hope for Much:
関の山
seki no yama
There are times when you are better off to quit when you're ahead, because a situation or a person is very difficult to handle. Seki no yama 関の山 describes a situation in which even the best effort will result in either a maintenance of the status quo, or possibly a deterioration in conditions:
Example 1:
説明してみても怒られるのが関の山だから、やめましょう。
Setsumei shite mite mo okorareru no ga seki no yama dakara, yamemashoo.
"Even if we try and explain it too him, the best we can hope for is for him to get mad at us, so let's just forget it."
Example 2:
徹夜で勉強しても試験室で寝てしまうのが関の山だから、今までの準備で受験しようと思います。
Tetsuya de benkyoo shite mo shiken-shitsu de nete shimau no ga seki no yama dakara, ima made no junbi de juken shiyoo to omoimasu.
"If I were to stay up all night studying, I would fall asleep in the exam room. So, I'll just take the test with the preparation that I've already done."
Notes: 徹夜 (てつや) staying up all night / 試験室(しけんしつ) exam room / 準備(じゅんび) preparation 受験(じゅけん)する to take an exam