In March 1990, in order to commemorate the 10th anniversary of the release of GUNPLA, the High Grade series was introduced, with the most advanced molding technology of the time. The styling setter was the well-known Kunio Ogawara. With scale of 1/144. HG is the first series using linked ball joints, glue-free snap assembly, multi-color molding technology, and variable systems, have greatly improved the appearance and mobility of the model. At that time, the HG-formed MS were Gundam, Gundam MK-II, Z Gundam, and ZZ Gundam. The price was set between 1,000 and 1,500 yen. Later, due to the deterioration of the special metal mold, after the HGUC version of RX-78-2 Gundam released in May 2001, the HG version was officially discontinued and replaced by the HGUC version. Therefore, the HG version of Gunpla became the first and the only series that is officially discontinued, in the history of Gunpla recently.
The replacement HGUC (High Grade Universal Century) series is only limited to MS that appeared in the universe century. This series also inherits HG's building steps and reduced painting difficulty. For pricing, due to the growth of molding technology, it is more expansive than the previous 1/144, but the overall quality is slightly higher than that of HG, and some units have simple internal structures. In recent years, with the maturity of technology, some new products, such as GP-02 and TR-1 [Hazel], have excellent performance in terms of internal structure and mobility. The characteristic of HGUC is that it attaches great importance to collection. Therefore, the setter of the suit is assumed by Hajime Katoki, and the ratio is unified to 1/144. The general price is 1,000 to 1,800 yen. But with special settings, there are also units that make the price goes outside this range.