ii kanji いい感じ

In Japanese, ii kanji いい感じ means literally "good feeling," but it's normally used to express your impression that something is favorable. That it looks good, that it feels good, that it seems good, or that it feels like it's going well, and so on.

It's the combination of the i-adjective ii いい, "good, " plus a noun form of the verb "to feel," kanjiru 感じる. This has nothing to do with the homonym kanji 漢字, "Chinese characters." And while kimochi ii 気持ちいい, "feeling good," sounds about the same it's used in a completely different way.

Manga: Killing Bites, Kiringu Baitsu キリングバイツ (Chapter 2)

• Examples
  
  • いい感じだった気がする
  • せっかくいい感じだったのに

Examples

For references, some examples of ii kanji いい感じ is use:

• ii kanji ni natta
  いい感じになった
  Became so it's ii kanji.
  • It wasn't ii kanji before, but it is now.
  • It has improved.
  • It looks, feels better now.
• ii kanji datta noni
  いい感じだったのに
  Even though it was ii kanji.
  • It was ii kanji before, but now something happened and it's not any longer.
  • Someone screwed up and ruined the thing, or something happened.
• ii kanji no hito
  いい感じの人
  A person [that gives you] a good feeling.
  • Someone that feels good to have around.
  • This phrase particularly refers to romantic interests: if you have someone who feels nice to have around, maybe you should start dating, etc.
  • Sometimes it means it feels nice in the sense that the relationship feels nice, that the relationship is going well.
• ii kanji no shashin
  いい感じの写真
  A photo [that gives you] a good feeling.
  • A photo that looks nice, that looks good, that seems well-taken.

Manga: Killing Bites, Kiringu Baitsu キリングバイツ (Chapter 2)

• *pours a ton of honey all over the pancakes like a savage animal.*
• hehe~~
  へへーー
  *chuckle*
• ii kanji
  いい感じ
  [This diabetic monstrosity looks good.]

いい感じだった気がする

Manga: Holy Land (Chapter 31)

• Context: everybody was kung fu fighting a guy is training his martial skills.
• *kicks defenseless tree.*
• na- nanka ima
  ii kanji datta
  ki ga suru...
  な　なんか今　いい感じだった気がする
  It's l... like now, [that] felt good, I think.
  • That might have been a good kick, is what he thinks.
  • ki ga suru 気がする
    To have a feeling something might be some way.
• demo chanto kereru
  no wa gokai ni ikkai
  kurai da na--...
  でもちゃんと蹴れるのは５回に一回位だなー･･･
  But [I'm only] able to kick properly around once every 5 times...
  • He needs to train more.
  • kereru 蹴れる
    To be able to kick.
  • keru 蹴る
    To kick.

せっかくいい感じだったのに

Manga: Kids on the Slope, Sakamichi no Apollon 坂道のアポロン (Chapter 2)

• Context: stuff didn't go keikaku doori.
• hontttttou ni baka da na kimi wa!
  本っっっっ当にバカだな君は！
  Reaaaaally [what an] idiot, you are!
• sekkaku ii kanji datta noni
  せっかくいい感じだったのに
  Even though, fortunately, everything was going well.
  • sekkaku せっかく
    Used before something that's fortunate to have happened. Something you'd rather not lose. (often used after you lost it, or before taking upon such rare opportunity.)
• ikki ni paa da!!
  一気にパアだ！！
  Suddenly it's all over!!
  • It's all gone in one sudden whoop!!
  • paa パア
    *poof*
    To go poof. To be gone. To disappear. To be lost.
• He's blaming someone, an "idiot," for making "everything that was going well" suddenly go poof. Through a grave mistake, presumably.