The 2SC5238 is covered by this 105 KB PDF, filed among schematics but named like a discrete-component datasheet. A 2SC prefix in the Japanese JIS scheme always marks an NPN bipolar transistor. The name carries no other information, so maker and package should be read from the sheet itself. On the bench it serves for pin identification, maximum ratings and gain specifications when testing with a multimeter's diode mode. It is equally useful when hunting for a cross-reference part.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @cyberlanelectonik. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.