The Waiver System is explained in the Yakyu Agreement (野球協約), sections 115 - 124.
Note: These are all paraphrased interpretations.
Section 115 - The Waiver:
Teams must submit an application to the commissioner's office. Once the application has been accepted, the player is automatically placed on Waivers. The list is available for every team to see, including the players. Other teams that are interested in the player will have 7 days to file a claim.
Section 116 - Illegal Use:
Teams can not enter into secret agreements with other clubs asking them not to file claims for the player.
Section 117 - Cancelling a Waiver Application:
Teams that place a player on Waivers can take back their applications within 3 days of the submission.
Section 118 - Player's Right to Refuse:
Players can refused to be placed on Waivers. They will, however, ended up being placed on the Disqualified Players List.
Section 119 - Multiple Teams File Claims:
If multiple teams file a claim for the player, teams from the same league as the team that placed the player on Waivers will get first dibs. If there are multiple teams from the same league and it's in the middle of a season, their winning percentages will determine who gets first dibs (the team with the worst percentages will have first choice). If it's not during the season, winning percentages from the previous season will be used.
Section 120 - No Claims are Filed:
If no teams file a claim for the player within 7 days, they will will become a free agent.
Section 121 - Successful Waiver Claim:
A team that successfully claims a player off Waivers will have to pay 4M yen to transfer the contract to their team.
Section 122 - Players Rights:
- Players cannot participate in any team functions while they are waivers.
- Once a player is claimed and placed on the 70-man roster, they are free to participate in team functions.
- Players will be considered a member of the 70-man roster of the team they originally belonged to until the Waiver paperwork is finalized.
Section 123 - Return to the Waiver:
A player that joins a team through the Waiver system can not be placed back on Waivers for at least 60 days.
Section 124 - Other Information:
Unless other conditions are set, these are the rules that cover players placed on Waivers.