-----------------------------------
お互いに， おたがいに
1. mutually, with each other, reciprocally, together, both
相互, 彼此, 相互, 一起, 两个都
-----------------------------------
良い， 好い， 善い， 佳い， 吉い， 宜い， よい， えい
1. good, excellent, fine, nice, pleasant, agreeable
2. sufficient, enough, ready, prepared
3. profitable (deal, business offer, etc.), beneficial
4. OK, all right, fine, no problem
5. easy to ...
tbd
-----------------------------------
間柄， 間がら， あいだがら
1. relationship, relation, terms (good, friendly, etc.)
tbd
は
1. indicates sentence topic
2. indicates contrast with another option (stated or unstated)
3. adds emphasis
指示句子的主题；表示与另一选项（无论是否明确提及）形成对比；表示强调
の
1. indicates possessive
2. nominalizes verbs and adjectives
3. substitutes for "ga" in subordinate phrases
4. (at sentence-end, falling tone) indicates a confident conclusion
5. (at sentence-end) indicates emotional emphasis
6. (at sentence-end, risi...
句尾起强调作用；助词，表示所有关系
