In In general, it is not recommended to invest in a property with tenants who rent the entire building, as it is risky for an investment property.
Even if you are paying a higher rent than the neighboring market rate, it is still risky as an investment property because you will have no rental income when that tenant moves out.
Please be aware that there are some dangerous cases where, for the purpose of selling the property at a high price, another corporation managed by a related party of the seller is allowed to rent the property at a higher rent than the neighboring market price and sell it as a high-yield property.