I forgot to pay my rent, what should I do?

The third point is whether the content of the contract is invalidated by the “interpretation of examples” in legal terms.
If the interpretation of a legal provision as written would lead to a result that is too unfair, the contract itself can be rejected as “merely illustrative” and its validity can be negated. To date, however, there does not appear to be any case in which the termination of a contract due to short-term rent arrears has been held invalid on the basis of a “case-by-case” interpretation.

Fourth, is there a violation of the provision in Japanese law (Consumer Contract Act) that states that “provisions that unilaterally prejudice the interests of consumers are invalid.
In the case of a building lease, which is based on a long-term contractual relationship, it may be judged as a provision “unilaterally prejudicing the interests of the consumer” to terminate the contract for only one month’s non-payment of rent. However, as there is no precedent for this, it is not clear whether it will always be interpreted in this way.

Ultimately, the content of the contract will be judged according to the thinking that has accumulated in the case law to date.
One way of thinking in the case law is the so-called “theory of breach of trust”. This is an attempt to protect the tenant’s right to reside by allowing the landlord to terminate the lease only if the “relationship of trust between the landlord and the tenant has ceased to exist.

It is important to talk to the landlord first to determine if you will have to move out after one month of non-payment of rent and to try to restore the relationship of trust.