Young solar-type stars are considered to have enormous starspots and show strong chromospheric emission lines because of their strong surface magnetic field. We discuss the dynamo activities of pre-main-sequence (PMS) stars and zero-age main-sequence (ZAMS) stars with respect to their periodic light variation caused by a starspot and with respect to the strength of the chromospheric emission lines. The Ca II infrared triplet (IRT) emission lines were investigated utilizing medium- and high-resolution spectroscopy. We conducted high-resolution spectroscopy with Subaru/HDS for 2 nights in 2021 and 2022. We also used additional archive spectra obtained by Keck/HIRES, VLT/UVES, and VLT/X-Shooter. Most PMS stars have narrow Ca II IRT emission lines whose intensities are as large as the maximum of the ZAMS stars. The light curves and spectrum of 26 PMS stars and 33 ZAMS stars were obtained from TESS photometric data. The amplitudes of the light curves are 0.001-0.552 mag. We found that the light variations and Ca II emission line strengths of PMS stars and ZAMS stars are as large as those of the most active superflare stars and two orders of magnitudes larger than those of the Sun, and are located on the extensions of the superflare stars. These results suggest that superflare stars link the properties of the Sun to those of the PMS stars and ZAMS stars.