The 2SC5588 is covered by this 332 KB PDF document. Apart from the part number the name gives no detail, so maker and revision are unknown until the file is opened. Per the JIS convention, a 2SC number refers to an NPN transistor of the high-frequency type. Such sheets help confirm base, collector and emitter positions, the absolute maximum ratings and the hFE classes used for selection. Always check the case marking and package on the board and confirm a cross-reference part meets or exceeds these limits.
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.