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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
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