How many shareholders there are doesn't matter much. Mainly depends on who the legal representative is, usually the signature of the legal representative. A company can have not only two shareholders, but also three shareholders, as long as there are no more than 50 people. The other party is 2 shareholders, 1 signature of shareholders. If the other shareholder doesn't want to, he can apply for the contract to be invalid. As long as you sign the contract, the contract is established.