Page 22 of the http://www.hataraku.metro.tokyo.jp/soudan-c/center/e/index.html PDF guide provides a clear direction for me…

The contract is of a “fixed term” that expires December 31, 2012. My dismissal is not based on any negative performance/conduct related issue. Rather Webnet is being fired, not me.

{ 2 Dismissal }
Dismissal is when an employer unilaterally terminates his/her employee’s employment contract. It is stipulated that “A Dismissal, when lacking objective rational grounds and is not considered to be appropriate in general societal terms, shall be seen as a misuse of that right and will thereby be invalid.” (Labor Contract Law 16)
Employees have the right to request a written certification of the reasons for their dismissal. (Article 22)
(1) Dismissal in case of workers hired for fixed period Employers are not allowed to dismiss employees with a fixed period of contract before the contract expires, except for in cases with an unavoidable reason (Article 628, Civil Law), or when a company goes bankrupt (Article 621, Civil Law). Even though a dismissal has an unavoidable reason, the employer shall have responsibility to pay compensation for the damage as far as the dismissal is attributable to the employer’s misstep. Or, if an employee was dismissed for reason such as breach of discipline and it is described in the rules of employment to that effect, the dismissal may still be recognized.