Solution : https://service.sap.com/sap/support/notes/78015 (SAP Service marketplace login required)
Key words : 
command      /usr/sap/put/exe/tp addtobuffer sapkl31h04 buffer=port_im2, tp 'addtobuffer sapkl31h04 buffer=port_im2, directory  /usr/sap/put/data, directory /usr/sap/put/bin, directory /usr/sap/put/data, sapserv3  directory ~/general/r3server/language/note, import transport order   sapkl31h04 und restart, instance   profile parameter zcsa/installed_languages, directory  ~/general/r3server/language/del_load, update tlsy7 set   status = 'a'
Related Notes : 
       
| 123235 | Language installation after patch import | 
| 98752 | Migration proposal pools (Release 3.0F/3.1x) | 
| 85580 | INST: 3.1H R/3 Inst. Japanese on NT | 
| 84427 | INST: 3.1H R/3 Inst. Japanese on UNIX | 
| 81439 | Additional Info: Upgrading to Japanese 31H DB2 | 
| 81438 | Additional Info: Upgrading to Japanese 31H MSSQLSRV | 
| 81434 | Additional Info: Upgrading to Japanese 31H ADABAS D | 
| 81433 | Additional Info: Upgrading to Japanese 31H INFORMIX | 
| 81432 | Additional Info: Upgrading to Japanese 31H ORACLE | 
| 77236 | Transport of customer translations between systems | 
| 76604 | Additional Info: Upgrading to 3.1H | 
| 74772 | Additional Info: Upgrading to 3.1H DB2/400 | 
| 73606 | Supported Languages and Code Pages | 
| 62178 | Device types for Japanese language | 
| 36156 | Language Availability 3.0x/3.1x | 
| 18601 | Frequently asked questions on language transport |