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Photometric monitoring by the Transiting Exoplanet Survey Satellite (TESS)has discovered not only periodic signals by transiting exoplanets but alsoepisodic or quasi-periodic dimming around young stellar objects. The mechanismsof the dimming of these objects, so-called "dippers", are thought to be relatedto the property of the accretion or the structure of protoplanetary disksespecially in regions close to the host star. Recently, we have created thecatalog of dippers from the one year of TESS Full Frame Image (FFI) data. Inthis paper, we report spectral features of four newly found dippers in thatcatalog and show that they potentially shed light on the dimming mechanisms. Wefound that all of the targets exhibit the H alpha emission line, which is anindicator of an ongoing accretion. Based on its line profiles and/or theirvariability, we characterized the properties of the disks of each source, whichcan support the dimming mechanisms due to a dusty disk wind or an accretionwarp. Also, we found an interesting dipper (TIC 317873721), "close-in binarydipper," showing the complex variability of the line profile and the largeradial velocity variation. Since the dimming intervals are similar to theorbital period of the binary, we suggest that the dips are caused by dust inthe warp of accretion from a circumbinary disk onto stars. Such a close-in ($<$0.1 au) binary dipper is rarely reported so far, further investigation willreveal the new aspect of the disk evolution and planetary formation.

Dippers from TESS Full-frame Images. II. Spectroscopic Characterization of Four Young Dippers