[SCHEDULE 13G/A (Amendment No. 1) 21Vianet Group, Inc (Name of Issuer) Class A Common Stock (Title of Class of Securities) 90138A103 (CUSIP Number) December 31, 2012 (Date of Event Which Requires Filing of this Statement) o Rule 13d-1(b) x Rule 13d-1(c) o Rule 13d-1(d) *The remainder of this cover page shall be filled out for a reporting person’s initial filing]
[Item 4. Ownership Please see Items 5 - 9 and 11 on eachver sheet for each Reporting Person Item 5. Ownership of Five Percent or Less of a Class Not Applicable Item 6. Ownership of More than Five Percent on Behalf of Another Person Not Applicable Item 7. Identification and Classification of the Subsidiary Which]
[13G CUSIP NO. 16950M107 PAGE 2 OF 11 PAGES 1 NAME OF REPORTING PERSON S.S. OR I.R.S. IDENTIFICATION NO. OF ABOVE PERSONS JAFCO Asia Technology Fund II 2 CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP x ¨ (a) 3 SEC USE ONLY]
